drm/amd/display: Use udelay when waiting between aux retries

[Why]
"IRQ_HPD Pulse Length Test" DP compliance test
fails. Test complains that certain DPCD registers
are not read within 100 ms.

[How]
msleep is inaccurate for small values. Used udelay
instead for accuracy.
Signed-off-by: John Barberiz <John.Barberiz@amd.com>
Reviewed-by: Wenjing Liu <Wenjing.Liu@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dce/dce_aux.c

@@ -516,7 +516,7 @@ bool dce_aux_transfer_with_retries(struct ddc_service *ddc,
 			}
 		}
 
-		msleep(1);
+		udelay(1000);
 	}
 	return false;
 }