gpio/xilinx: Fix kernel-doc
gpio/xilinx: Fix kernel-doc

Some documentation were not following the kernel-doc format.
Backporting patch from Xilinx git repository.

Suggested-by: Michal Simek <b20e59da6aeb5cea6c82b021069d69f63616c55d@xilinx.com>
Acked-by: Michal Simek <b20e59da6aeb5cea6c82b021069d69f63616c55d@xilinx.com>
Acked-by: Alexandre Courbot <301cd6a3ea50a894b4b51e385c5eb12b9a4ffc0c@nvidia.com>
Signed-off-by: Ricardo Ribalda Delgado <39bb74b16720293e1449e36465485b27216fbd6d@gmail.com>
Signed-off-by: Linus Walleij <9cd9d802d23c0ed5e224beabf4ae4a5c478746ef@linaro.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs