Driver core: add suspend() and resume() to struct device_type

In cases when there are devices of different types in the same class
we can't use class's implementation of suspend and resume methods and
we need to add them to struct device_type instead.

Also fix error handling in resume code (we should not try to call
class's resume method iof bus's resume method for the device failed.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>