UMS: f_mass_storage: Added cdrom option to UMS-lun-devices

This patch allows programs to change the cdrom option at runtime
through sysfs.

Indentation corrected.

Change-Id: I4beab26133e3ac325ecbded1414d4e6215e377e8
USB: f_mass_storage: 2048 block size for cdrom devices

Enables computer Bios's to recognize the cdrom device like most
other cdrom devices. This allows people to boot ISOs from their
phone.

Indentation corrected.

Change-Id: Ia3ff20cb5b40da71da9702695d2ff974727deda8
Small optimization