drm/i915: don't capture DERRMR for VLV/CHV

DERRMR isn't valid for VLV/CHV. Don't capture it for them.

Suggested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://lore.kernel.org/r/4563cc7eb567ac508b84717c3708a4e48aa8b7bb.1744630147.git.jani.nikula@intel.com


Signed-off-by: Jani Nikula <jani.nikula@intel.com>