ALSA: hda - Avoid choose same converter for unused pins

For Intel Haswell HDMI codecs, the pins choose converter 0 by default.
This would cause conflict when playing audio on unused pins,the pin with
physical device connected would get audio data too.
i.e. Pin 0/1/2 default choose converter 0, pin 1 has HDMI monitor connected.
when play audio on Pin 0 or pin 2, pin 1 could get audio data too.

This patch configure unused pins to choose different converter.

Signed-off-by: Wang Xingchao <xingchao.wang@linux.intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>