input: sensors: fix MPU6050 output scaling issue.

Convert accelerometer and gyroscope output according sensor full
measurement range. This allow gyroscope output to be convert
correctly and fix gyroscope output value issue.

Change-Id: I47790615c3549142878da6ee55c9d87e4b77fb1c
Signed-off-by: Bingzhe Cai <bingzhec@codeaurora.org>