commit f883982d upstream.

HP EliteBook 755 G2 with ALC3228 (ALC280) codec [103c:221c] requires
the known fixup (ALC269_FIXUP_HEADSET_MIC) for making the headset mic
working.  Also, it suffers from the loopback noise problem, so we
should disable aamix path as well.
Reported-by: Derick Eddington <derick.eddington@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>