configs: meson64_android: define raw parts for bootloader

configs: meson64_android: define raw parts for bootloader

Per the android documentation[1]:
- the mmc2boot0 partition should be labeled "bootloader".
- the mmc2boot1 partition should be labeled "bootenv".

Also the u-boot documentation[2] refers to a BOOT1_OFFSET of 1 block.

Define 2 raw partitions to store the bootloaders and the bootenv.

[1] https://source.android.com/setup/build/devices#vim3-fastboot
[2] https://u-boot.readthedocs.io/en/latest/board/amlogic/khadas-vim3l.html

Suggested-by: Gary Bisson <gary.bisson@boundarydevices.com>
Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Link: https://lore.kernel.org/r/20220107163913.3393563-1-mkorpershoek@baylibre.com
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>