configs: meson64_android: add PANIC stage for SYSTEM fails

If bootloader was updated without running oem format, reboot will cause
boot loop because the SYSTEM stage fails.

Add a final PANIC stage running fastboot to permit recovery.

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