arm64: dts: uniphier: route on-board device IRQ to GPIO controller for PXs3

Commit 429f203e ("arm64: dts: uniphier: route on-board device IRQ
to GPIO controller") missed to update this DTS.  It becames a real
problem when arm and arm64 trees are merged together.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>