usb: gadget: mass_storage: added sysfs entry for cdrom to LUNs

This patch adds a "cdrom" sysfs entry for each mass_storage LUN, just
like "ro" sysfs entry. This allows switching between USB and CD-ROM
emulation without reinserting the module or recompiling the kernel.

Change-Id: I115e3c8b5cf6e473cb081ef84f7be451ecdc1f0f
freezer: define try_to_freeze_nowarn if CONFIG_FREEZER=n

Fixes build since:
  0e432e6 HACK: ARM: disable sleeping while atomic warning in do_signal

Change-Id: I451217171c6beb55ab4d190e1248ddbc9a2d9516
Signed-off-by: Ben Jones <ben.jones@imgtec.com>
Kernel Version: AK.037-FAUX.017b