OMAPDSS: HDMI: Split audio_enable into audio_enable/disable

To improve readability, split the audio_enable HDMI IP operation
into two separate functions for enabling and disabling audio.
The audio_enable function is also modified to return an error value.

While there, update these operations for the OMAP4 IP accordingly.

Signed-off-by: Ricardo Neri <ricardo.neri@ti.com>
diff --git a/drivers/video/omap2/dss/ti_hdmi.h b/drivers/video/omap2/dss/ti_hdmi.h
index 1f58b84..88fdc1c 100644
--- a/drivers/video/omap2/dss/ti_hdmi.h
+++ b/drivers/video/omap2/dss/ti_hdmi.h
@@ -108,7 +108,9 @@
 
 #if defined(CONFIG_SND_OMAP_SOC_OMAP4_HDMI) || \
 	defined(CONFIG_SND_OMAP_SOC_OMAP4_HDMI_MODULE)
-	void (*audio_enable)(struct hdmi_ip_data *ip_data, bool start);
+	int (*audio_enable)(struct hdmi_ip_data *ip_data);
+
+	void (*audio_disable)(struct hdmi_ip_data *ip_data);
 #endif
 
 };
@@ -183,6 +185,7 @@
 void ti_hdmi_4xxx_phy_dump(struct hdmi_ip_data *ip_data, struct seq_file *s);
 #if defined(CONFIG_SND_OMAP_SOC_OMAP4_HDMI) || \
 	defined(CONFIG_SND_OMAP_SOC_OMAP4_HDMI_MODULE)
-void ti_hdmi_4xxx_wp_audio_enable(struct hdmi_ip_data *ip_data, bool enable);
+int ti_hdmi_4xxx_wp_audio_enable(struct hdmi_ip_data *ip_data);
+void ti_hdmi_4xxx_wp_audio_disable(struct hdmi_ip_data *ip_data);
 #endif
 #endif