Driver core: add platform_create_bundle() helper

Many legacy-style module create singleton platform devices themselves,
along with corresponding platform driver. Instead of replicating error
handling code in all such drivers, provide a helper that allocates and
registers a single platform device and a driver and binds them together.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>