PCI: Rework default handling of suspend and resume

Rework the handling of suspend and resume of PCI devices which have
no drivers or the drivers of which do not provide any suspend-resume
callbacks in such a way that their standard PCI configuration
registers will be saved and restored with interrupts disabled.  This
should prevent such devices, including PCI bridges, from being
resumed too late to be able to function correctly during the resume
of the other PCI devices that may depend on them.

Also, to remove one possible source of future confusion, drop the
default handling of suspend and resume for PCI devices with drivers
providing the 'pm' object introduced by the new suspend-resume
framework (there are no such PCI drivers at the moment).

This patch addresses the regression from 2.6.26 tracked as
http://bugzilla.kernel.org/show_bug.cgi?id=12121 .

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>