drm/amd/pm: Add APIs for device access checks

Wrap the checks before device access in helper functions and use them
for device access. The generic order of APIs now is to do input argument
validation first and check if device access is allowed.

Signed-off-by: Lijo Lazar <lijo.lazar@amd.com>
Reviewed-by: Feifei Xu <feifei.xu@amd.com>
Reviewed-by: Asad Kamal <asad.kamal@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>