U-Boot 2021.10 has been released.
Rebase mediatek patches on top of new release and remove some patches
which have been merged upstream.
Tested on Bananapi BPi-R2 (mt7623), Bananapi BPi-R64 (mt7622) and
Linksys E8450 (mt7622).
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
