drm/amd/powerplay: add get_clock_by_type interface for display

This patch adds get_clock_by_type interface for display, in smu v11 didn't have
the implementation.

Signed-off-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Evan Quan <evan.quan@amd.com>
Reviewed-by: Kevin Wang <Kevin1.Wang@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>