drm/amd/pm: smu_v14_0_0: use SoftMin for gfxclk in set_soft_freq_limited_range

drm/amd/pm: smu_v14_0_0: use SoftMin for gfxclk in set_soft_freq_limited_range

In smu_v14_0_0_set_soft_freq_limited_range(), the gfxclk floor is
programmed via SetHardMinGfxClk together with SetSoftMaxGfxClk. Under
power_dpm_force_performance_level=high this pins HardMin to peak gfxclk.

In PMFW arbitration HardMin has higher priority than SoftMax, so the
firmware thermal/PPT throttler cannot clamp gfxclk via SoftMax once
HardMin is set to peak. Replace SetHardMinGfxClk with SetSoftMinGfxclk
so the driver still requests peak performance but the firmware
throttler retains the ability to clamp gfxclk under thermal/PPT
pressure. SoftMax handling is unchanged and no other clock domains
are affected.

Signed-off-by: Priya Hosur <Priya.Hosur@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>