ALSA: Add more jack button slots

Some devices have more flexible microphone detection and can detect
a wider range of buttons.

Signed-off-by: Mark Brown <[e-mail]>
Signed-off-by: Takashi Iwai <[e-mail]>

include/sound/jack.h

···
 	SND_JACK_BTN_0		= 0x4000,
 	SND_JACK_BTN_1		= 0x2000,
 	SND_JACK_BTN_2		= 0x1000,
+	SND_JACK_BTN_3		= 0x0800,
+	SND_JACK_BTN_4		= 0x0400,
+	SND_JACK_BTN_5		= 0x0200,
 };
 
 struct snd_jack {
···
 	int type;
 	const char *id;
 	char name[100];
-	unsigned int key[3];   /* Keep in sync with definitions above */
+	unsigned int key[6];   /* Keep in sync with definitions above */
 	void *private_data;
 	void (*private_free)(struct snd_jack *);
 };