ASoC: msm: 8x10: Fix button detection voltage thresholds

Adjust button detection thresholds to improve button
detection as button ranges should  be scaled in sync
to the recent changes for using 2.7V for micbias.

CRs-Fixed: 587697
Change-Id: Ibfa5bb87e08f434410b23b74ed2fa0af018efc5e
Signed-off-by: Simmi Pateriya <simmip@codeaurora.org>