drm/amd/powerplay: bug fixs for getsmuclockinfo

The .syspll_id and .dfsdid are not initialzed correctly. And
le32_to_cpu transfer is needed on the output.

Signed-off-by: Evan Quan <evan.quan@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>