ARM: dts: msm: Disable vibrator overdrive for pmi632

There are scenarios where Vbat is lower than overdrive
voltage causing the vibrator to fail. Disabling overdrive
does not have a performance impact, hence disable it.

Change-Id: I26d54057903e6898e7d1a7a851417f6b2c5af161
Signed-off-by: Tirupathi Reddy <tirupath@codeaurora.org>