examples/c++: light-sensor now catches CTRL+C and exits polling loop.
examples/c++: light-sensor now catches CTRL+C and exits polling loop.

Signed-off-by: Henry Bruce <57ea958cad66de244404958c9a01f7a4ad51b29e@intel.com>

srware/upm,srware/upm,srware/upm,srware/upm,srware/upm