drm/amd/display: Add some missing register definitions

[Why&How]
Add some missing register definitions and rearrange some others to
maintain consistency with related definitions.

Acked-by: Stylon Wang <stylon.wang@amd.com>
Signed-off-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Reviewed-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/amd/display: Add missing registers for ACP

We are missing some ACP registers/mask value for some specific ASICs.
This commit includes it to those ASICs that support it.

Signed-off-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/amdgpu: Add and use seperate reg headers for dcn302

Currently we are using dcn3 reg headers for dcn302. The offsets are
different between the two so they need seperate headers.

Add dcn302 header files and use these instead of dcn3 header

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