Driver core: Revert "Fix Firmware class name collision"

This reverts commit 109f0e93

.

The original patch breaks BIOS updates on all Dell machines. The path to
the firmware file for the dell_rbu driver changes, which breaks all of
the userspace tools which rely on it.

Note that this patch re-introduces a problem with i2c name collision
that was previously fixed by this patch.

Signed-off-by: Michael E Brown <michael_e_brown@dell.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>