configs: khadas-vim3*_android: fix environment saving

The environment is used to configure some additional boot features such as:
* extra boot arguments
* enable AVB (Android Verified Boot) verification

Right now, we cannot store it in eMMC:

  Loading Environment from nowhere... OK

Fix it by enabling the appropriate options in the defconfig

Fixes: b749d5ec ("configs: meson64_android: define raw parts for bootloader")
Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20231026-fix-saveenv-v1-1-6aa59be65481@baylibre.com


Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>