ALSA: hda - Intel HDMI audio support

Add support for Intel G45 integrated HDMI audio codecs.

This initial release supports:
	- 2 channel stereo sound output
	- report monitor's ELD information

Signed-off-by: Wu Fengguang <wfg@linux.intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>