drm/amd/powerplay: correct force clock level related settings for vega20 (v2)

1. The min/max level is determined by soft_min_level/soft_max_level.
2. Vega20 comes with pptable v3 which has no vdd related
table(vdd_dep_on_socclk, vdd_dep_on_mclk) support.
3. Vega20 does not support separate fan feature control(enable or
disable).

v2: squash in fixes:
- bug fix for force dpm level settings
- fix wrong data type

Signed-off-by: Evan Quan <evan.quan@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>