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

This is mostly about support for the Allwinner R528/T113s SoC, which is
reportedly the same die as the Allwinner D1, but with the two
Arm Cortex-A7 cores activated instead of the RISC-V one.
Using sunxi code outside of arch/arm proved to be difficult, so apart
from enabling this Arm SoC, the patches also prepare for more refactoring
to get the D1 nicely supported some day:
- We get rid of some Kconfig (hard-)coded GPIO pins, responsible for
  enabling regulators.
- The GPIO code is moved out of arch/arm, into drivers/gpio.
- Some definitions are moved out of header files under asm/arch.
- Some T113s/D1 specific definitions are guarded by a generic Kconfig
  symbol (CONFIG_SUNXI_GEN_NCAT2).
- The DRAM controller initialisation code is located under drivers/ram.
- The base SoC .dtsi files are shared (under arch/riscv, as in Linux).

Of course there are also the usual new SoC specific patches, like clock
and pinmux descriptions, alongside a rework of the pinctrl code, since
Allwinner changed the GPIO register layout, for the first time since
sunxi's inception.
On top of this the PSCI code sees some update, to provide SMP services
for R528/T113s boards. Many thanks to Sam for providing this code and
staying strong through the review cycles.
The final patch enables support for one popular board, I hope to see
more DTs and defconfigs contributed in the future!

Many thanks to all the various contributors, testers and reviewers,
that series was a real team effort!