drm/i915: Pass the region ID rather than a bitmask to HAS_REGION()

The name 'HAS_REGION()' suggests we are checking for a single
region, so seem more sensible to pass in the region ID rather
than a bitmask.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240502121423.1002-2-ville.syrjala@linux.intel.com


Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>