drm/i915: Extract mchbar_reg()

Stop repeating the same logic to determine the correct
config space register for MCHBAR.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231101114212.9345-4-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
This commit is contained in:
Ville Syrjälä 2023-11-01 13:42:10 +02:00
commit e5aaad610f