ASoC: wcd9xxx: update button press thresholds

Recently it is observed that DCE read with button press
has changed for higher buttons if micbias is disabled
while vddio is enabled during playback. With this change
button press thresholds need to be adjusted as well to
correctly detect button press.

CRs-Fixed: 755384
Change-Id: Idd555fe4a2592268cc747cc35615b0cf7214790f
Signed-off-by: Simmi Pateriya <simmip@codeaurora.org>