drm/i915: Deal with bigjoiner vs. DRRS

DRRS operates on transcoder level, so we should only poke at it from
the master crtc rather than letting every joined pipe give it
potentially conflicting input.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220315132752.11849-9-ville.syrjala@linux.intel.com


Reviewed-by: Manasi Navare <manasi.d.navare@intel.com>