drm/amd/display: Add null checks for 8K60 lightup

[WHY & HOW]
Add some null checks to fix an issue where 8k60
tiled display fails to light up.

Cc: Mario Limonciello <mario.limonciello@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Reviewed-by: Charlene Liu <charlene.liu@amd.com>
Acked-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Muhammad Ahmed <ahmed.ahmed@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/core/dc.c

@@ -3178,7 +3178,7 @@ static bool update_planes_and_stream_state(struct dc *dc,
 			struct pipe_ctx *otg_master = resource_get_otg_master_for_stream(&context->res_ctx,
 					context->streams[i]);
 
-			if (otg_master->stream->test_pattern.type != DP_TEST_PATTERN_VIDEO_MODE)
+			if (otg_master && otg_master->stream->test_pattern.type != DP_TEST_PATTERN_VIDEO_MODE)
 				resource_build_test_pattern_params(&context->res_ctx, otg_master);
 		}
 	}

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

@@ -5190,6 +5190,9 @@ bool dc_resource_acquire_secondary_pipe_for_mpc_odm_legacy(
 	sec_next = sec_pipe->next_odm_pipe;
 	sec_prev = sec_pipe->prev_odm_pipe;
 
+	if (pri_pipe == NULL)
+		return false;
+
 	*sec_pipe = *pri_pipe;
 
 	sec_pipe->top_pipe = sec_top;