Under vega10 virtualuzation, smu ip block will not be added.
Therefore, we need add pp clk query and force dpm level function
at amdgpu_virt_ops to support the feature.

v2: add get_pp_clk existence check and use kzalloc to allocate buf

v3: return -ENOMEM for allocation failure and correct the coding style
Signed-off-by: Yintian Tao <yttao@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>