Merge branch '2022-06-28-Kconfig-migrations' into next

- Convert a large number of CONFIG symbols to Kconfig.  Of note is a
  large chunk of USB symbols (and dead code removal), ensuring all
  SPL/TPL/VPL symbols have an appropriate dependency, largely (but not
  entirely) removing the testing of CONFIG_SPL_BUILD in board headers,
  and allowing CONFIG_EXTRA_ENV_TEXT and CONFIG_EXTRA_ENV_SETTINGS to
  co-exist as this facilities migration of many platforms.