This patch adds device id and revision into system info entry at CGS,
it's able to get PCI device id and revision id from amdgpu, it might
get more info in future.

PCI device id will be also used on powerplay part at current.
Suggested-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>