platform driver: fix incorrect use of 'platform_bus_type' with 'struct device_driver'

This patch fixes the bug reported in
	http://bugzilla.kernel.org/show_bug.cgi?id=11681

.

"Lots of device drivers register a 'struct device_driver' with
the '.bus' member set to '&platform_bus_type'. This is wrong,
since the platform_bus functions expect the 'struct device_driver'
to be wrapped up in a 'struct platform_driver' which provides
some additional callbacks (like suspend_late, resume_early).
The effect may be that platform_suspend_late() uses bogus data
outside the device_driver struct as a pointer pointer to the
device driver's suspend_late() function or other hard to
reproduce failures."(Lothar Wassmann)

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Acked-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>