drm/amdgpu: Add xcc specific functions

Add more XCC specific functions and use them from IP block functions.
RLC, CP functions are further split to have xcc specific versions.

Signed-off-by: Lijo Lazar <lijo.lazar@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>