sensors: Add the sensor handle and type define

Add the sensor handle and type define for the sensor class device
drivers. The define is used for the sensor class device driver
parameters "handle" and "type". By using the define, people could
easily get the "handle" and "type" name.

Change-Id: I3e985a831d428fe3e921b2aecd8018b92d139302
Signed-off-by: Jie Cheng <rockiec@codeaurora.org>