Merge branch 'master' of https://source.denx.de/u-boot/custodians/u-boot-sunxi

Merge branch 'master' of https://source.denx.de/u-boot/custodians/u-boot-sunxi

These patches add support for the new Allwinner A523/A527/T527 SoC (all
same die), alongside with defconfigs for three boards using one of those
SoCs.
The patches are the usual combination of refactoring (of the SPL clock
code this time), tweaks to existing drivers to support peripherals in
their A523 versions, and new drivers for pincontrol and clocks. A big
chunk is of course the DRAM controller init routines, many thanks to
Jernej and Mikhail for providing this code, after a big reverse
engineering effort.
Since the DTs for the three supported boards have been merged into the
kernel repo recently, this is concluded by cherry-picks of those
patches, and the defconfig files to finally enable booting those boards.

The patches have been sitting around for a while, and folks are already
using them, so it's now time to get them into the tree.

Gitlab CI passed, and I booted that briefly on those three boards, plus
on some other SoCs to spot potential regressions.