Do not increment the parent firmware's reference count when any other firmware image in the module is registered.  Instead, do it when the other image is itself referenced.
Do not increment the parent firmware's reference count when any other
firmware image in the module is registered.  Instead, do it when the
other image is itself referenced.

This allows a module with multiple firmware images to be automatically
unloaded when none of the firmware images are in use.

Discussed with:	jhb@ (on -hackers)

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase