PNP: Fix compile error in quirks.c

Fix the compile error:

drivers/pnp/quirks.c:393:2: error: implicit declaration of function 'pcibios_bus_to_resource'

that occurs when building with CONFIG_PCI unset.  The quirk is only
relevent to Intel devices, so we could use "#if defined(CONFIG_X86) &&
defined(CONFIG_PCI)" instead, but testing CONFIG_X86 is not strictly
necessary.

Fixes: cb171f7a

 (PNP: Work around BIOS defects in Intel MCH area reporting)
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>