linuxPackages.wireguard: fix the build on linux 5.4.76

Patch copied from https://github.com/archlinux/svntogit-packages/blob/packages/wireguard-dkms/trunk/lts.diff

This fixes:

```
In file included from <command-line>:
/build/source/src/compat/compat-asm.h:44: warning: "SYM_FUNC_START" redefined
   44 | #define SYM_FUNC_START ENTRY
      |
In file included from /build/source/src/compat/compat-asm.h:9,
                 from <command-line>:
/nix/store/cz60577g5hwk78c2z7rhxl21bklaqr0d-linux-5.4.77-dev/lib/modules/5.4.77-hardened/source/include/linux/linkage.h:218: note: this is the location of the previous definition
  218 | #define SYM_FUNC_START(name)    \
      |
In file included from <command-line>:
/build/source/src/compat/compat-asm.h:45: warning: "SYM_FUNC_END" redefined
   45 | #define SYM_FUNC_END ENDPROC
      |
In file included from /build/source/src/compat/compat-asm.h:9,
                 from <command-line>:
/nix/store/cz60577g5hwk78c2z7rhxl21bklaqr0d-linux-5.4.77-dev/lib/modules/5.4.77-hardened/source/include/linux/linkage.h:265: note: this is the location of the previous definition
  265 | #define SYM_FUNC_END(name)    \
      |
/build/source/src/crypto/zinc/blake2s/blake2s-x86_64.S: Assembler messages:
/build/source/src/crypto/zinc/blake2s/blake2s-x86_64.S:50: Error: invalid character '(' in mnemonic
/build/source/src/crypto/zinc/blake2s/blake2s-x86_64.S:176: Error: invalid character '(' in mnemonic
/build/source/src/crypto/zinc/blake2s/blake2s-x86_64.S:180: Error: invalid character '(' in mnemonic
/build/source/src/crypto/zinc/blake2s/blake2s-x86_64.S:257: Error: invalid character '(' in mnemonic
make[3]: *** [/nix/store/cz60577g5hwk78c2z7rhxl21bklaqr0d-linux-5.4.77-dev/lib/modules/5.4.77-hardened/source/scripts/Makefile.build:348: /build/source/src/crypto/zinc/blake2s/blake2s-x86_64.o] Error 1
make[3]: *** Waiting for unfinished jobs....
In file included from <command-line>:
/build/source/src/compat/compat-asm.h:44: warning: "SYM_FUNC_START" redefined
   44 | #define SYM_FUNC_START ENTRY
      |
In file included from /build/source/src/compat/compat-asm.h:9,
                 from <command-line>:
/nix/store/cz60577g5hwk78c2z7rhxl21bklaqr0d-linux-5.4.77-dev/lib/modules/5.4.77-hardened/source/include/linux/linkage.h:218: note: this is the location of the previous definition
  218 | #define SYM_FUNC_START(name)    \
      |
In file included from <command-line>:
/build/source/src/compat/compat-asm.h:45: warning: "SYM_FUNC_END" redefined
   45 | #define SYM_FUNC_END ENDPROC
      |
In file included from /build/source/src/compat/compat-asm.h:9,
                 from <command-line>:
/nix/store/cz60577g5hwk78c2z7rhxl21bklaqr0d-linux-5.4.77-dev/lib/modules/5.4.77-hardened/source/include/linux/linkage.h:265: note: this is the location of the previous definition
  265 | #define SYM_FUNC_END(name)    \
      |
/build/source/src/crypto/zinc/chacha20/chacha20-x86_64.S: Assembler messages:
/build/source/src/crypto/zinc/chacha20/chacha20-x86_64.S:123: Error: invalid character '(' in mnemonic
/build/source/src/crypto/zinc/chacha20/chacha20-x86_64.S:185: Error: invalid character '(' in mnemonic
/build/source/src/crypto/zinc/chacha20/chacha20-x86_64.S:187: Error: invalid character '(' in mnemonic
/build/source/src/crypto/zinc/chacha20/chacha20-x86_64.S:319: Error: invalid character '(' in mnemonic
/build/source/src/crypto/zinc/chacha20/chacha20-x86_64.S:1016: Error: invalid character '(' in mnemonic
/build/source/src/crypto/zinc/chacha20/chacha20-x86_64.S:1616: Error: invalid character '(' in mnemonic
/build/source/src/crypto/zinc/chacha20/chacha20-x86_64.S:1620: Error: invalid character '(' in mnemonic
/build/source/src/crypto/zinc/chacha20/chacha20-x86_64.S:1810: Error: invalid character '(' in mnemonic
/build/source/src/crypto/zinc/chacha20/chacha20-x86_64.S:1812: Error: invalid character '(' in mnemonic
/build/source/src/crypto/zinc/chacha20/chacha20-x86_64.S:1959: Error: invalid character '(' in mnemonic
make[3]: *** [/nix/store/cz60577g5hwk78c2z7rhxl21bklaqr0d-linux-5.4.77-dev/lib/modules/5.4.77-hardened/source/scripts/Makefile.build:348: /build/source/src/crypto/zinc/chacha20/chacha20-x86_64.o] Error 1
make[2]: *** [/nix/store/cz60577g5hwk78c2z7rhxl21bklaqr0d-linux-5.4.77-dev/lib/modules/5.4.77-hardened/source/Makefile:1729: /build/source/src] Error 2
make[1]: *** [/nix/store/cz60577g5hwk78c2z7rhxl21bklaqr0d-linux-5.4.77-dev/lib/modules/5.4.77-hardened/source/Makefile:179: sub-make] Error 2
make: *** [Makefile:26: module] Error 2
builder for '/nix/store/hll3sjyrwa55arzlsxnbacqdd8s842l1-wireguard-1.0.20200908.drv' failed with exit code 2
```

1 files changed, 4 insertions, 0 deletions

diff --git a/pkgs/os-specific/linux/wireguard/default.nix b/pkgs/os-specific/linux/wireguard/default.nix
index b8b65fecafc2..ef81dd54a736 100644
--- a/pkgs/os-specific/linux/wireguard/default.nix
+++ b/pkgs/os-specific/linux/wireguard/default.nix
@@ -14,6 +14,10 @@ stdenv.mkDerivation rec {
     sha256 = "1nd2kc3c62907kxm1084dw7krd8xsy3hxydmcpz4jvk03vm5dnkg";
   };
 
+  patches = [
+    ./linux-5.4.76-fix.patch
+  ];
+
   hardeningDisable = [ "pic" ];
 
   KERNELDIR = "${kernel.dev}/lib/modules/${kernel.modDirVersion}/build";