PM: platform_bus and late_suspend/early_resume

Teach platform_bus about the new suspend_late/resume_early PM calls,
issued with IRQs off.  Do we really need sysdev and friends any more,
or can janitors start switching its users over to platform_device so
we can do a minor code-ectomy?

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>