drm: bridge/dw_hdmi: introduce interface to setting sample rate

Introduce dw_hdmi_set_sample_rate(), which allows us to configure the
audio sample rate, setting the CTS/N values appropriately.

Tested-by: Yakir Yang <ykk@rock-chips.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/include/drm/bridge/dw_hdmi.h b/include/drm/bridge/dw_hdmi.h
index de13bfc..763af51 100644
--- a/include/drm/bridge/dw_hdmi.h
+++ b/include/drm/bridge/dw_hdmi.h
@@ -12,6 +12,8 @@
 
 #include <drm/drmP.h>
 
+struct dw_hdmi;
+
 enum {
 	DW_HDMI_RES_8,
 	DW_HDMI_RES_10,
@@ -59,4 +61,7 @@
 		 void *data, struct drm_encoder *encoder,
 		 struct resource *iores, int irq,
 		 const struct dw_hdmi_plat_data *plat_data);
+
+void dw_hdmi_set_sample_rate(struct dw_hdmi *hdmi, unsigned int rate);
+
 #endif /* __IMX_HDMI_H__ */