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

- Add and enable watchdog driver
- Prepare for SYSRESET driven AXP poweroff
- Prepare for SoCs without MMC2
- Some fixes for extending SPL (SPL-DM for RISC-V)
- Some preparations for proper VBUS management
- Fix secure monitor move