drm/i915: Disable all planes before modesetting any pipes

drm/i915: Disable all planes before modesetting any pipes

Let's disable planes on all pipes affected by the modeset before
we start doing the actual modeset. This means we have less
random planes enabled during the modeset, and it also mirrors
what we already do when enabling pipes on skl+ since we enable
planes on all pipes as the very last step. As a bonus we also
nuke a bunch og bigjoiner special casing.

I've occasionally pondered about going even furher here and
doing the pre_plane_update() stuff for all pipes first, then
actually disabling the planes, and finally running the rest
of the modeset sequence. This would potentially allow
parallelizing all the extra vblank waits across multiple pipes,
and would make the plane disable even more atomic. But let's
go one step a time here.

Cc: José Roberto de Souza <jose.souza@intel.com>
Reviewed-by: Manasi Navare <manasi.d.navare@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211022103304.24164-4-ville.syrjala@linux.intel.com
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>