drm/amd/pp: Convert clock unit to KHz as defined

Convert clock unit 10KHz to KHz as the data sturct defined.
e.g.
struct pp_clock_with_latency {
	uint32_t clocks_in_khz;
	uint32_t latency_in_us;
};
Meanwhile revert the same conversion in display side.

Acked-by: Alex Deucher <alexander.deucher@amd.com>
Acked-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>