arm64: dts: uniphier: correct on-board device IRQ number for PXs3

Commit ba5b5034 ("arm64: dts: uniphier: route on-board device IRQ
to GPIO controller for PXs3") has incorrect update.

Fixes: ba5b5034

 ("arm64: dts: uniphier: route on-board device IRQ to GPIO controller for PXs3")
Signed-off-by: Dai Okamura <okamura.dai@socionext.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>