msm: camera: Add state for sensor power up

The sensor and flash triggers I2C transactions during close.
These transactions should be done only if the sensor is in
power up state. Add necessary state variables to check
the state of sensor.

Change-Id: Id41a39b12e2d368899c308e24a02eb357db78e64
Signed-off-by: Rajakumar Govindaram <rajakuma@codeaurora.org>