ALSA: snd-aoa: handle master-amp if present

Some machines have a master amp GPIO that needs to be toggled to
get sound output, in addition to speaker/headphone/line-out amps.
This makes snd-aoa handle it, if present in the device tree, thus
making snd-aoa be able to output sound on PowerMac3,6, which was
previously handled by snd-powermac which also doesn't use the
master amp GPIO.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/aoa/aoa-gpio.h b/sound/aoa/aoa-gpio.h
index ee64f5d..6065b03 100644
--- a/sound/aoa/aoa-gpio.h
+++ b/sound/aoa/aoa-gpio.h
@@ -34,10 +34,12 @@
 	void (*set_headphone)(struct gpio_runtime *rt, int on);
 	void (*set_speakers)(struct gpio_runtime *rt, int on);
 	void (*set_lineout)(struct gpio_runtime *rt, int on);
+	void (*set_master)(struct gpio_runtime *rt, int on);
 
 	int (*get_headphone)(struct gpio_runtime *rt);
 	int (*get_speakers)(struct gpio_runtime *rt);
 	int (*get_lineout)(struct gpio_runtime *rt);
+	int (*get_master)(struct gpio_runtime *rt);
 
 	void (*set_hw_reset)(struct gpio_runtime *rt, int on);