ALSA: hda - Add more hint options for IDT/Sigmatel codecs

Allow more options to be set/reset via hwdep hint entry.
hp_detect, gpio_mask, gpio_dir, gpio_data, eapd_mask and eapd_switch
can be checked.

For example, to disable hp_detect on the fly,
	# echo "hp_detect=0" > /sys/class/sound/hwC0D0/hints

Signed-off-by: Takashi Iwai <tiwai@suse.de>