staging: iio: tsl2x7x: add range checking to tsl2x7x_write_raw

The CALIBBIAS and INT_TIME masks in tsl2x7x_write_raw did not have any
range checking in place so this patch adds the appropriate range
checking. The defines TSL2X7X_ALS_GAIN_TRIM_{MIN,MAX} are also
introduced by this patch.

Signed-off-by: Brian Masney <masneyb@onstation.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>