[ACPI] PCI can now get suspend state from firmware

pci_choose_state() can now call
	platform_pci_choose_state()
		and ACPI can answer

http://bugzilla.kernel.org/show_bug.cgi?id=4277



Signed-off-by: David Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>