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.
diff --git a/configs/boston64r6el_defconfig b/configs/boston64r6el_defconfig
index 72b3649..d2af060 100644
--- a/configs/boston64r6el_defconfig
+++ b/configs/boston64r6el_defconfig
@@ -8,13 +8,13 @@
 CONFIG_SYS_LOAD_ADDR=0xffffffff88000000
 CONFIG_ENV_ADDR=0xFFFFFFFFBFFE0000
 CONFIG_TARGET_BOSTON=y
-CONFIG_SYS_LITTLE_ENDIAN=y
 CONFIG_CPU_MIPS64_R6=y
 # CONFIG_MIPS_BOOT_CMDLINE_LEGACY is not set
 # CONFIG_MIPS_BOOT_ENV_LEGACY is not set
 CONFIG_MIPS_BOOT_FDT=y
 CONFIG_SYS_MEMTEST_START=0x80000000
 CONFIG_SYS_MEMTEST_END=0x90000000
+CONFIG_SYS_LITTLE_ENDIAN=y
 CONFIG_DISTRO_DEFAULTS=y
 CONFIG_FIT=y
 CONFIG_FIT_VERBOSE=y