drm/amdgpu/powerplay: add initial renoir_ppt.c for renoir (v3)

Add renoir_ppt and map ppsmc to amdgpu_smu.h

v2: squash in ppsmc updates (Alex)
v3: squash in driver_if updates (Alex)

Signed-off-by: Aaron Liu <aaron.liu@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>