drm/i915: Move PLANE_BUG_CFG bit definitions to the correct place

All other skl+ universal plane register bit definitions are next
to the pipe A register definition. Move the PLANE_BUF_CFG bit
definitions there as well.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230320090522.9909-7-ville.syrjala@linux.intel.com


Reviewed-by: Juha-Pekka Heikkila <juhapekka.heikkila@gmail.com>