gpio: xilinx: Fix kernel-doc warnings
gpio: xilinx: Fix kernel-doc warnings

Fix kernel-doc format:
- Add gpio-width description
- Remove additional "inited" variable description
- Add return value description - xgpio_remove

Signed-off-by: Michal Simek <b20e59da6aeb5cea6c82b021069d69f63616c55d@xilinx.com>
Signed-off-by: Linus Walleij <9cd9d802d23c0ed5e224beabf4ae4a5c478746ef@linaro.org>

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