ASoC: msm: program button high thresholds correctly

Program button 4,5,6 and 7 thresholds correctly
so as to avoid unnecessary button press interrupts
when mic impedance is low enough to cause mic
voltage greater than 500mV.

Change-Id: I934785123413d81ac6d0511ece186d15d18fa752
Signed-off-by: Yeleswarapu Nagaradhesh <nagaradh@codeaurora.org>