Try to mitigate potential future driver core api changes by padding to
struct bus_type, struct device_driver, struct class, and struct device.
Based on a patch from Michal Marek <mmarek@suse.cz> from the SLES kernel
Bug: 151154716
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I6892cde6481ba775789f0c02239dcfde3a26b56e