ARM: dts: ixp4xx: use phandle-based GPIOs in mi424wr

ARM: dts: ixp4xx: use phandle-based GPIOs in mi424wr

Convert remaining legacy integer GPIO specifiers to phandle-based
descriptors in intel-ixp42x-actiontec-mi424wr.dtsi.

All other GPIOs in this file already use &gpio0/&gpio1. These are the
last remaining legacy users in the IXP4xx DTS files.

Signed-off-by: Mohamed Ayman <mohamedaymanworkspace@gmail.com>
Link: https://lore.kernel.org/20260428191029.809462-1-mohamedaymanworkspace@gmail.com
Signed-off-by: Linus Walleij <linusw@kernel.org>
Link: https://lore.kernel.org/r/20260505-ixp4xx-dts-v1-1-02f4a92a9697@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>