USB_DFU was added in meson64.h but is missing in libretech-ac.h,
fix this to enable DFU RAM boot for libretech-ac.

Fixes 4aa027b3f8 ("configs: meson64: add alternate USB DFU boot target")

Link: https://lore.kernel.org/r/20231102-libretech-ac-fix-dfu-v1-1-112379165028@linaro.org
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>

- In ARMv8 NXP Layerscape platforms we also need to make use of
  CONFIG_SYS_RELOC_GD_ENV_ADDR now, do so.
- On ENV_IS_IN_REMOTE, CONFIG_ENV_OFFSET is never used, drop the define
  to 0.
- Add Kconfig entry for ENV_ADDR.
- Make ENV_ADDR / ENV_OFFSET depend on the env locations that use it.
- Add ENV_xxx_REDUND options that depend on their primary option and
  SYS_REDUNDAND_ENVIRONMENT
- On a number of PowerPC platforms, use SPL_ENV_ADDR not CONFIG_ENV_ADDR
  for the pre-main-U-Boot environment location.
- On ENV_IS_IN_SPI_FLASH, check not for CONFIG_ENV_ADDR being set but
  rather it being non-zero, as it will now be zero by default.
- Rework the env_offset absolute in env/embedded.o to not use
  CONFIG_ENV_OFFSET as it was the only use of ENV_OFFSET within
  ENV_IS_IN_FLASH.
- Migrate all platforms.

Cc: Wolfgang Denk <wd@denx.de>
Cc: Joe Hershberger <joe.hershberger@ni.com>
Cc: Patrick Delaunay <patrick.delaunay@st.com>
Cc: uboot-stm32@st-md-mailman.stormreply.com
Signed-off-by: Tom Rini <trini@konsulko.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
Reviewed-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>

LibreTech AC is a single board computer manufactured by Libre Technology
with the following specifications:

 - Amlogic S805X ARM Cortex-A53 quad-core SoC @ 1.2GHz
 - ARM Mali 450 GPU
 - 512MiB DDR4 SDRAM
 - 10/100 Ethernet
 - HDMI 2.0 4K/60Hz display
 - 40-pin GPIO header
 - 4 x USB 2.0 Host
 - eMMC, SPI NOR Flash
 - Infrared receiver

The u-boot specific code is the same as the P212 support,
so use the P212 board support code with a distinct defconfig
and config include files.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>