Adding new option to manually mount the target file system.
- manual -> Installs Arch Linux ARM on a manually mounted device/s at /tmp/arfs (note: No partitioning nor formatting will be done).
This can be useful when you want to create complex file systems with specific folders mounted in specific partitions (e.g. separate / and /home). It will require to do the partitioning and the formatting manually and then mount the partitions under /tmp/arfs/.