drm/amd/display: do not treat clip_rect size change as a scaling change

drm/amd/display: do not treat clip_rect size change as a scaling change

[why]
With previous ODM + MPO policy we will only allocate pipes when MPO plane
has intersection with current ODM slice. With this policy we have to indicate
scaling change when plane clip is updated in case plane clip change causes
MPO plane to go in or out current ODM slice.
With new ODM + MPO policy we allocate pipe independent from plane clip size
so we no longer treat it as a scaling change. There no need to do a full update
due to clip size change anymore.

Reviewed-by: Jun Lei <jun.lei@amd.com>
Acked-by: Tom Chung <chiahsuan.chung@amd.com>
Signed-off-by: Wenjing Liu <wenjing.liu@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>