Merge patch series "phycore-am62/4: Add more boot sources"

Daniel Schultz <d.schultz@phytec.de> says:

This patch stack extends the phyCORE-AM62x/AM64x U-Boot by following boot
sources:

  - Load U-Boot with USB DFU
  - Load a Linux and initramfs from OSPI/QSPI NOR flash
  - Load a Linux and rootfs from Network

Moreover, it adds required changes to the environment to boot an A/B
system with RAUC and includes some minor fixes.