PCI PM: Move pci_has_legacy_pm_support

Move pci_has_legacy_pm_support() closer to the functions that
call it.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>