pci: Introduce pci_find_present

This works like pci_dev_present but instead of returning boolean returns
the matching pci_device_id entry.  This makes it much more useful.  Code
bloat is basically nil as the old boolean function is rewritten in terms of
the new one.

This will be used by the updated VIA PCI quirks for one

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>