drm/amd/display: Add a Precise Delay Routine

Fix DP compliance failures 4.2.2.12, 4.3.1.21, 4.9.1.19
caused by imprecise delay on fsleep().

Reviewed-by: Aric Cyr <aric.cyr@amd.com>
Signed-off-by: Fangzhi Zuo <Jerry.Zuo@amd.com>
Signed-off-by: Wayne Lin <wayne.lin@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.c

@@ -272,7 +272,7 @@ void dp_wait_for_training_aux_rd_interval(
 	struct dc_link *link,
 	uint32_t wait_in_micro_secs)
 {
-	fsleep(wait_in_micro_secs);
+	usleep_range_state(wait_in_micro_secs, wait_in_micro_secs, TASK_UNINTERRUPTIBLE);
 
 	DC_LOG_HW_LINK_TRAINING("%s:\n wait = %d\n",
 		__func__,