ACPI: always enable CONFIG_PNPACPI on CONFIG_ACPI kernels

We removed the ACPI motherboard driver which handled
the ACPI=y, PNP=n case, so now we need to enforce that
PNP & PNPACPI are always enabled for ACPI kernels.

Most major distros ship this way this already.

Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index 20eacc2..2d21fed 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -13,6 +13,7 @@
 	depends on IA64 || X86
 	depends on PCI
 	depends on PM
+	select PNP
 	default y
 	---help---
 	  Advanced Configuration and Power Interface (ACPI) support for