i965: Fix eu/subslice warning
i965: Fix eu/subslice warning

Older gen platforms do not actually return a value for sublice and eu total
(IMO, confusingly) they return -ENODEV. This patch defers the SSEU setup until
we have the actual GPU generation to avoid useless warnings when running on
older platforms with older kernels.

Reported-by: Mark Janes <dc19c7a5044e1b627d35321fa5e1121fad8638f9@intel.com>
Signed-off-by: Ben Widawsky <cf148a1c890adeeb4308e9e093ed95f3d05c8318@intel.com>
Reviewed-by: Kenneth Graunke <bd2562f754ec92342f93f61c25d731e290a2ffa8@whitecape.org>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler