drm/amd/display: Convert 10kHz clks from PPLib into kHz

Except special naming as *_in_khz, The default clock unit in powerplay
is in 10KHz. so need to * 10 as expecting clock frequency in display
is in kHz.

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Rex Zhu <Rex.Zhu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>