drm/amd/display: Reset flip_immediate to topmost plane

[Why]
When checking if we want to disable GSL or not,
we should reset flip_immediate to be the flip type
of the topmost plane before looping through the
other planes.

[How]
Set flip_immediate to be the flip type of the topmost
plane before looping through the other planes.
Signed-off-by: Alvin Lee <alvin.lee2@amd.com>
Reviewed-by: Aric Cyr <Aric.Cyr@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c

@@ -1204,6 +1204,9 @@ void dcn20_pipe_control_lock(
 		    (!flip_immediate && pipe->stream_res.gsl_group > 0))
 			dcn20_setup_gsl_group_as_lock(dc, pipe, flip_immediate);
 
+	if (pipe->plane_state != NULL)
+		flip_immediate = pipe->plane_state->flip_immediate;
+
 	temp_pipe = pipe->bottom_pipe;
 	while (flip_immediate && temp_pipe) {
 	    if (temp_pipe->plane_state != NULL)