drm/i915/fbc: No FBC+double wide pipe

FBC and double wide pipe are mutually exclusive. Disable FBC when
we have to resort to double wide.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211124113652.22090-20-ville.syrjala@linux.intel.com


Reviewed-by: Mika Kahola <mika.kahola@intel.com>