drm/radeon/kms: rework audio polling timer

Rework HDMI audio polling timer, only enable it when
at least one HDMI encoder needs it. Preparation for
replacing it with irq support.

Signed-off-by: Christian König <deathsimple@vodafone.de>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/radeon_mode.h b/drivers/gpu/drm/radeon/radeon_mode.h
index 4a086c0..dd451c5 100644
--- a/drivers/gpu/drm/radeon/radeon_mode.h
+++ b/drivers/gpu/drm/radeon/radeon_mode.h
@@ -345,6 +345,7 @@
 	enum radeon_rmx_type rmx_type;
 	struct drm_display_mode native_mode;
 	void *enc_priv;
+	int audio_polling_active;
 	int hdmi_offset;
 	int hdmi_config_offset;
 	int hdmi_audio_workaround;