gpio: 104-idio-16: Fix coding style issues

Fixed multiple bare uses of 'unsigned' without int.
Reported by checkpatch.

Signed-off-by: Navin Sankar Velliangiri <navin@linumiz.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>