msm: camera: Sensor kernel restructure

Add new sensor utility functions for I2C write,
I2C read, EEPROM read and gpio operation. This is
to provide better control and flexibility for user
space sensor module.

Change-Id: I534c9c51768fcd8d00713bdcf87b63083a606ced
Signed-off-by: Jack Wang <jackwang@codeaurora.org>