drm/amd/display: changing sr exit latency

[Why]
Hardware team remeasured, need to update timings
to increase latency slightly and avoid intermittent
underflows.

[How]
sr exit latency update.
Signed-off-by: Martin Leung <martin.leung@amd.com>
Reviewed-by: Alvin Lee <Alvin.Lee2@amd.com>
Acked-by: Qingqing Zhuo <Qingqing.Zhuo@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/dcn30/dcn30_resource.c

@@ -181,7 +181,7 @@ struct _vcs_dpi_soc_bounding_box_st dcn3_0_soc = {
 		},
 	.min_dcfclk = 500.0, /* TODO: set this to actual min DCFCLK */
 	.num_states = 1,
-	.sr_exit_time_us = 12,
+	.sr_exit_time_us = 15.5,
 	.sr_enter_plus_exit_time_us = 20,
 	.urgent_latency_us = 4.0,
 	.urgent_latency_pixel_data_only_us = 4.0,