Added cdrom option to luns

Change-Id: Ic3b97f8bf58171cfa51f57c2674f2ddba0cafe13
Fix for cdrom

Change-Id: I13956c8b1ccd01d6314a0fe0dac45c7dab84435c
2048 block size for cdrom-f_mass_storage devices

Bios will recognize the cdrom device like most other cdrom
devices. This allows people to boot ISOs from their phone.

Original by Andreas Kemnade:
http://www.spinics.net/lists/linux-usb/msg25178.html

Change-Id: Id8fba96e1683f6daa6330b1e59f4a4ca4fe5c271