ALSA: hda - define is_haswell() to check if a display audio codec is Haswell

To apply Haswell specific fixings, this patch defines is_haswell() to check
whether a display audio codec is Haswell, to avoid explicitly checking Haswell
vendor ID everywhere.

Signed-off-by: Mengdong Lin <mengdong.lin@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>