Driver core: Revert "Fix Firmware class name collision"

patch 7d640c4a in mainline.

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>