iio: light sensor: Fix a panic in the tsl2563 driver.

Add a wrapper for this driver around the IIO_CHAN() wrapper to make channel
parameters more readable.  This fixes a panic caused by the info_masks being
accidentally passed in as channel2 parameters which easily surpass the size
of the iio_modifier_names_light array.

Signed-off-by: Bryan Freed <bfreed@chromium.org>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>