drm/amdgpu: Switch to smuio func to get gpu clk counter

Switch to smuio callback to query gpu clock counter

Signed-off-by: Hawking Zhang <Hawking.Zhang@amd.com>
Reviewed-by: Likun Gao <Likun.Gao@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>