misc: isa1200: correct overdrive enablement bit shift

Overdrive enablement bit sits at 6th bit of control register 0.
Current shifting overwrites overdrive high bit.

Signed-off-by: Chun Zhang <chunz@codeaurora.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
misc: isa1200: Change mutex for isa1200 vibrator

Change i2c client device mutex to local driver mutex
for isa1200 vibrator which is used while enabling and
disabling the clock.

CRs-Fixed: 545512
Change-Id: I4f61c629c503c658410b5c14da2e1612b82ec201
Signed-off-by: Shantanu Jain <shjain@codeaurora.org>