Merge tag 'mediatek-for-master-2026-04-07' of https://source.denx.de/u-boot/custodian...

This is the first wave of MediaTek changes for this merge window. We
also expect to be sending another decent-sized pull request later for
the backlog of patches that are currently waiting on dependencies or
need little more time for review.

* Fixes for cargo-culted issues in mach-mediatek init.c files.
* Some consistency cleanups of recently added Genio boards (510/700/1200).
* Some pinctrl improvements to support newer MediaTek SOCs (mt8189 compatible).
* New devicetree and config for Genio 520/720 EVK boards (can boot to eMMC or SD).
* New CPU-specific functions to read vendor-specific CPU info at runtime.