drm/amd/display: build scaling params when a new plane is appended

drm/amd/display: build scaling params when a new plane is appended

[why & how]
We are boundling changes in plane state and build scaling params
together. This is to simplify DML code so DML doesn't need to build
scaling params. We are also avoiding rebuilding scaling params for
planes without scaling changes.

Reviewed-by: Dillon Varone <dillon.varone@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>