drm/amd/pm: restore SCLK settings after S0ix resume

drm/amd/pm: restore SCLK settings after S0ix resume

User-configured SCLK(GPU core clock)frequencies were not persisting
across S0ix suspend/resume cycles on smu v14 hardware.
The issue occurred because of the code resetting clock frequency
to zero during resume.

This patch addresses the problem by:
- Preserving user-configured values in driver and sets the
  clock frequency across resume
- Preserved settings are sent to the hardware during resume

Signed-off-by: mythilam <mythilam@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Yang Wang <kevinyang.wang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>