drm/amd/display/dc: drop dm_delay_in_microseconds

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

drivers/gpu/drm/amd/display/dc/core/dc_link_hwss.c

@@ -127,7 +127,7 @@ static bool edp_receiver_ready_T9(struct dc_link *link)
 			break;
 		if (result != DC_OK)
 			break;
-		dm_delay_in_microseconds(link->ctx, 100); //MAx T9
+		udelay(100); //MAx T9
 	} while (++tries < 50);
 	return result;
 }
@@ -271,7 +271,7 @@ void dp_retrain_link_dp_test(struct dc_link *link,
 			pipes[i].stream->sink->link != NULL &&
 			pipes[i].stream_res.stream_enc != NULL &&
 			pipes[i].stream->sink->link == link) {
-			dm_delay_in_microseconds(link->ctx, 100);
+			udelay(100);
 
 			pipes[i].stream_res.stream_enc->funcs->dp_blank(
 					pipes[i].stream_res.stream_enc);

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

@@ -137,7 +137,7 @@ static void dce_dmcu_set_psr_enable(struct dmcu *dmcu, bool enable, bool wait)
 					if (psr_state == 0)
 						break;
 				}
-				dm_delay_in_microseconds(dmcu->ctx, 10);
+				udelay(10);
 		}
 	}
 }
@@ -378,7 +378,7 @@ static void dcn10_dmcu_set_psr_enable(struct dmcu *dmcu, bool enable, bool wait)
 			if (psr_state == 0)
 				break;
 		}
-		dm_delay_in_microseconds(dmcu->ctx, 500);
+		udelay(500);
 	}
 
 	/* assert if max retry hit */

drivers/gpu/drm/amd/display/dc/dm_services.h

@@ -404,9 +404,6 @@ bool dm_read_persistent_data(struct dc_context *ctx,
 		unsigned int size,
 		struct persistent_data_flag *flag);
 
-void dm_delay_in_microseconds
-	(struct dc_context *ctx, unsigned int microSeconds);
-
 bool dm_query_extended_brightness_caps
 	(struct dc_context *ctx, enum dm_acpi_display_type display,
 			struct dm_acpi_atif_backlight_caps *pCaps);