drm/rockchip: vop2: Enforce scaling workaround in plane_check

drm/rockchip: vop2: Enforce scaling workaround in plane_check

It seems only cluster windows are capable of applying downscaling when
the source region has an odd width. Instead of applying a workaround
inside atomic_update, fail the plane check if this is requested.

Signed-off-by: Daniel Stone <daniels@collabora.com>
Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patch.msgid.link/20251215-vop2-atomic-fixups-v5-4-83463c075a8d@collabora.com