libgcrypt: always pass build and host to configure

When building for aarch32 on aarch64 with extraPlatforms, libgcrypt
fails to build because it tries to guess the host platform from uname,
which returns the wrong result in this case. We fix this by always
telling libgcrpyt what platform to build for.

pkgs/development/libraries/libgcrypt/default.nix

@@ -30,6 +30,10 @@ stdenv.mkDerivation rec {
   configureFlags = [ "--with-libgpg-error-prefix=${libgpgerror.dev}" ]
    ++ stdenv.lib.optional stdenv.hostPlatform.isMusl "--disable-asm";
 
+  # Necessary to generate correct assembly when compiling for aarch32 on
+  # aarch64
+  configurePlatforms = [ "host" "build" ];
+
   # Make sure libraries are correct for .pc and .la files
   # Also make sure includes are fixed for callers who don't use libgpgcrypt-config
   postFixup = ''