drm/amd/powerplay: introduce smu power source type to handle AC/DC source for each asic

This patch introduces new smu power source type, it's to handle the different
AC/DC source defines for each asic with the same smu ip.

Signed-off-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Kevin Wang <kevin1.wang@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>