sensors: Add the class device support for cm36283 sensor

Add the sensor class device support for the cm36283 light and
proximity sensor. By using the class device, the driver will
create the subfolder in the "/sys/class/sensors/". The userspace
app could detect the sensors by searching this folder.

Change-Id: I4d96ed54ee647069a5f1cf592c4aea1d8636a0f5
Signed-off-by: Jie Cheng <rockiec@codeaurora.org>