Third round of iio fixes for the 3.16 cycle. * Lots of hid sensors component drivers had a bug due to a local variable whose name suggested it was returned from the read_raw function not infact being returned (ret vs ret_type). Fixed and unused ret removed. * Block a possible race condition in tcs3472 by locking around some dependant i2c messages. * Fix bug in the am335x driver fifo setup that occurs if the final channel enabled takes certain values.