drm/amdgpu/pm: add some common ppt functions for SMU IP v13.0.x

Add some common ppt functions that will be used by SMU IP v13.0.x
and drop the not used function smu_v13_0_mode2_reset.

Signed-off-by: Tim Huang <tim.huang@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>