drm/amd/display: Fix RGB MPO underflow with multiple displays

[WHY]
With RGB MPO enabled, playing a video with multiple displays connected
results in underflow when closing the video window

[HOW]
Reverted the old change to fix this problem, which prevented pipe splits
for multiple display configurations and caused high MCLK speeds during
idle. Added a two step call to dc_update_planes_and_stream, first time
with pipe split disabled and the second time with pipe split enabled,
which fixed the underflow issue
Reviewed-by: Aric Cyr <Aric.Cyr@amd.com>
Acked-by: Anson Jacob <Anson.Jacob@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Angus Wang <angus.wang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c

@@ -1069,7 +1069,7 @@ static const struct dc_debug_options debug_defaults_drv = {
 		.timing_trace = false,
 		.clock_trace = true,
 		.disable_pplib_clock_request = true,
-		.pipe_split_policy = MPC_SPLIT_AVOID_MULT_DISP,
+		.pipe_split_policy = MPC_SPLIT_DYNAMIC,
 		.force_single_disp_pipe_split = false,
 		.disable_dcc = DCC_ENABLE,
 		.vsr_support = true,

drivers/gpu/drm/amd/display/dc/dcn30/dcn30_resource.c

@@ -840,7 +840,7 @@ static const struct dc_debug_options debug_defaults_drv = {
 	.timing_trace = false,
 	.clock_trace = true,
 	.disable_pplib_clock_request = true,
-	.pipe_split_policy = MPC_SPLIT_AVOID_MULT_DISP,
+	.pipe_split_policy = MPC_SPLIT_DYNAMIC,
 	.force_single_disp_pipe_split = false,
 	.disable_dcc = DCC_ENABLE,
 	.vsr_support = true,

drivers/gpu/drm/amd/display/dc/dcn302/dcn302_resource.c

@@ -211,7 +211,7 @@ static const struct dc_debug_options debug_defaults_drv = {
 		.timing_trace = false,
 		.clock_trace = true,
 		.disable_pplib_clock_request = true,
-		.pipe_split_policy = MPC_SPLIT_AVOID_MULT_DISP,
+		.pipe_split_policy = MPC_SPLIT_DYNAMIC,
 		.force_single_disp_pipe_split = false,
 		.disable_dcc = DCC_ENABLE,
 		.vsr_support = true,

drivers/gpu/drm/amd/display/dc/dcn303/dcn303_resource.c

@@ -193,7 +193,7 @@ static const struct dc_debug_options debug_defaults_drv = {
 		.timing_trace = false,
 		.clock_trace = true,
 		.disable_pplib_clock_request = true,
-		.pipe_split_policy = MPC_SPLIT_AVOID_MULT_DISP,
+		.pipe_split_policy = MPC_SPLIT_DYNAMIC,
 		.force_single_disp_pipe_split = false,
 		.disable_dcc = DCC_ENABLE,
 		.vsr_support = true,