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>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>