MediaTek published their current U-Boot patchset on github:
https://github.com/mtk-openwrt/u-boot/commits/mtksoc
Import the platform patches from there (`00-mtk-*.patch`), arrange,
them nicely, drop no longer needed local patches and rebase on top of
U-Boot 2021.04-rc3.
Tested and works well on Linksys E8450 (snand-1ddr) as well as
Bananapi BPi-R64 (sdmmc-2ddr, emmc-2ddr).
Signed-off-by: Daniel Golle <daniel@makrotopia.org>