drm/amd/display: Add DCN3 OPP header

Add support to program the DCN3 OPP (Output Plane Processing)

HW Blocks:

+-------+
| OPP |
+-------+
|
v
+--------+
| OPTC |
+--------+
|
v
+--------+ +--------+
| DIO | | DCCG |
+--------+ +--------+

Signed-off-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>