input: sensor: remove the input open/close interface for mpu3050

The mpu3050_input_open and mpu3050_input_close hold an usage counter
of the device and may prevent the device entering runtime suspend.
So remove the code to save the runtime power consumption for mpu3050.

Change-Id: Idb55b3388c39851291b5330fa7add5d12374cf80
Signed-off-by: Oliver Wang <mengmeng@codeaurora.org>