drm/i915/guc: Use major_minor version for filename

Load guc firmware from file with major_minor number
in filename instead of using symolic link with only
major number.

This change is so that new firmwares can only be used
with a kernel change. This in case there is a regression
with a new firmware, it won't be used by default without
some testing.

Issue: VIZ-7713
Signed-off-by: Tom O'Rourke <Tom.O'Rourke@intel.com>
Signed-off-by: Nick Hoath <nicholas.hoath@intel.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by:  <peter.antoine@intel.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>