gpio: visconti: Fix fwnode of GPIO IRQ

gpio: visconti: Fix fwnode of GPIO IRQ

BugLink: https://bugs.launchpad.net/bugs/1978240
commit 171865dab096da1ab980a32eeea5d1b88cd7bc50 upstream.

The fwnode of GPIO IRQ must be set to its own fwnode, not the fwnode of the
parent IRQ. Therefore, this sets own fwnode instead of the parent IRQ fwnode to
GPIO IRQ's.

Fixes: 2ad74f40dacc ("gpio: visconti: Add Toshiba Visconti GPIO support")
Signed-off-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>