drm/amd/display: Add OTG check for set AV mute

[Why && How]
OTG can be disabled before setting dpms on. Add check to skip wait
when setting AV mute if OTG is disabled.
Reviewed-by: Wenjing Liu <wenjing.liu@amd.com>
Acked-by: Roman Li <roman.li@amd.com>
Signed-off-by: Leo (Hanghong) Ma <hanghong.ma@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/hwss/dcn30/dcn30_hwseq.c

@@ -813,7 +813,7 @@ void dcn30_set_avmute(struct pipe_ctx *pipe_ctx, bool enable)
 				enable);
 
 		/* Wait for two frame to make sure AV mute is sent out */
-		if (enable) {
+		if (enable && pipe_ctx->stream_res.tg->funcs->is_tg_enabled(pipe_ctx->stream_res.tg)) {
 			pipe_ctx->stream_res.tg->funcs->wait_for_state(pipe_ctx->stream_res.tg, CRTC_STATE_VACTIVE);
 			pipe_ctx->stream_res.tg->funcs->wait_for_state(pipe_ctx->stream_res.tg, CRTC_STATE_VBLANK);
 			pipe_ctx->stream_res.tg->funcs->wait_for_state(pipe_ctx->stream_res.tg, CRTC_STATE_VACTIVE);