Merge branch 'rework-irq-handling-in-mtk_eth_soc'

Frank Wunderlich says:

====================
rework IRQ handling in mtk_eth_soc

From: Frank Wunderlich <frank-w@public-files.de>

This series introduces named IRQs while keeping the index based way
for older dts.
Further it makes some cleanup like adding consts for index access and
avoids loading first IRQ which was not used on non SHARED_INT SoCs.
====================

Link: https://patch.msgid.link/20250619132125.78368-1-linux@fw-web.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>