input: sensors: add place property for MPU6050 driver

The place property is to configure the position of sensor mounting.
For different devices the relative position to first pin will be
different.

CRs-fixed: 655796
Change-Id: I39e1da93106d81679166e89534dd6cebb1a0d096
Signed-off-by: Bingzhe Cai <bingzhec@codeaurora.org>