[U-Boot] PSCI for H3

Hi everyone,

I got my Orange Pi PC booting U-boot now, using Hans' sunxi-wip branch that includes Jens' patches.

For PSCI and SMP, it seems the H3 follows the structure of previous sun8i SoCs. The CPUCFG registers line up. The manual doesn't have the PRCM, so I'll have to dig through the SDK.

One other thing is the SMTA, or Secure Memory Touch Arbiter, which we last encountered issues with on the A31s. This controls non-secure access to a whole bunch of peripherals, which we'll need to enable for Linux to run non-secure.

Anyway, this is just a preliminary evaluation of the work needed for PSCI. Nothing has actually been done or tested.

Regards ChenYu