Camera: Fix camera problem when reboot

Camera: Fix camera problem when reboot

Fix problem camera led remains active after reboot

The camera is an USB camera. When system reboot the usb
bus is not powered off, so camera remains active. Camera
led will be closed untill the system init and reset devices.

To resolve this bug, we need to register a reboot notifier
in camera driver, so that camera can receive "restart" notifier
when system reboot, it will call notifier callback function
to close the camera led.

Issue: AXIA-1417
Change-Id: Ia6cc19d645419f7dfea9e3fa4ebb67b583eaddda
Signed-off-by: juntingwang <Junting.Wang@windriver.com>