Find7: fix headset detection and buttons

Change-Id: I51ba60ac22e8422dd88d6b49bd484513ab43264d

Conflicts:
	sound/soc/codecs/wcd9320.c
	sound/soc/codecs/wcd9xxx-mbhc.c
	sound/soc/msm/msm8974.c

Conflicts:
	arch/arm/boot/dts/msm8974.dtsi
	sound/soc/codecs/wcd9320.c
	sound/soc/codecs/wcd9xxx-mbhc.c
	sound/soc/codecs/wcd9xxx-mbhc.h
	sound/soc/msm/msm8974.c