Merge branch '2022-04-21-assorted-improvements'

- For the environment, add a arch_env_get_location hook and make use of
  it on some NXP platforms (so that boards can override SoCs).
- Remove some unused squashfs code from SPL
- Resync am335x beaglebone related DTS files
- Enable SPL_SEPARATE_BSS if SPL_BSS_START_ADDR is used