Install grub2 on non-arm architectures

src/freedombone-image-customise

 chroot "$rootdir" apt-get install -y libnss-mdns libnss-myhostname libnss-gw-name nano man ntp
 chroot "$rootdir" apt-get install -y locales locales-all debconf wireless-tools wpasupplicant
 chroot "$rootdir" apt-get install -y usbutils cryptsetup zsh pinentry-curses iotop bc
+if [[ $ARCHITECTURE == 'i386' || $ARCHITECTURE == 'i686' || $ARCHITECTURE == 'amd64' || $ARCHITECTURE == 'x86_64' ]]; then
+    chroot "$rootdir" apt-get install -y grub2
+fi
 
 sed -i "s|#host-name=.*|host-name=${PROJECT_NAME}|g" $rootdir/etc/avahi/avahi-daemon.conf
 sed -i "s|host-name=.*|host-name=${PROJECT_NAME}|g" $rootdir/etc/avahi/avahi-daemon.conf