intel: Make intel_chipset handle devid directly.

This will make these macros reusable from intel_decode.c, which
doesn't have a bufmgr_gem context, without faking the struct.  We
should generally only be using these macros from bufmgr_gem context
setup anyway.

Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Eugeni Dodonov <eugeni@dodonov.net>