ASoC: msm8952: Change keycode mapping and linein_th

Change the key code mapping of buttons as below
according to Android spec. Report SW_LINEOUT_INSERT
if headset speaker impedance is larger than 5 Kohm

Button0 0-70 ohm - hook key
Button1 110-180 ohm - voice assist
Button2 210-290 ohm - volume up
Button3 360-680 ohm - volume down

CRs-Fixed: 924091
Change-Id: Ic4500c6ccbd1db7d6a6c2932f30ae00e7d61d062
Signed-off-by: Asish Bhattacharya <asishb@codeaurora.org>