i965/skl: Utilize new 5th bit for gateway messages
i965/skl: Utilize new 5th bit for gateway messages

Modify comment as spotted by Matt, and Chris Forbes

Signed-off-by: Ben Widawsky <cf148a1c890adeeb4308e9e093ed95f3d05c8318@intel.com>
Reviewed-by: Matt Turner <789b315743a28dd066a4ba1459c35951c291d8a6@gmail.com>
Reviewed-by: Jordan Justen <a79006884ba9cf5f4f7fcbb92a15b208780d8c97@intel.com>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler