intel/ibexpeak: Fix missing ACPI PIRQ entries

Fix regression after commit
  7f5efd9 intel/bd82x6x: Use generated ACPI PIRQ

The call to inject generated PIRQ entry was not added when
the static entries as default_irq_route.asl file was removed
from boards using intel/nehalem southbridge.

Change-Id: I8097c1ab729d1eb91a6d547ef13948c1e21eca10
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/25965
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Matthias Gazzari <mail@qtux.eu>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/southbridge/intel/ibexpeak/Kconfig

@@ -29,6 +29,7 @@ config SOUTH_BRIDGE_OPTIONS # dummy
 	select PCIEXP_ASPM
 	select PCIEXP_COMMON_CLOCK
 	select SOUTHBRIDGE_INTEL_COMMON
+	select SOUTHBRIDGE_INTEL_COMMON_RCBA_PIRQ
 	select SOUTHBRIDGE_INTEL_COMMON_SMBUS
 	select SOUTHBRIDGE_INTEL_COMMON_SPI
 	select HAVE_USBDEBUG_OPTIONS