input: sensors: refine MPU6050 resume logic

MPU6050 axis standby bits are not set by default after
sensor power cycle, this results gyroscope and accelerometer
stay active and consume more power.

CRs-fixed: 731419
Change-Id: I606de419ca46695e9c1d451fa3860d10627683d0
Signed-off-by: Bingzhe Cai <bingzhec@codeaurora.org>