gpio-pch: Support interrupt function

Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 04499c1..de5fea6 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -388,6 +388,7 @@
 config GPIO_PCH
 	tristate "Intel EG20T PCH / OKI SEMICONDUCTOR ML7223 IOH GPIO"
 	depends on PCI && X86
+	select GENERIC_IRQ_CHIP
 	help
 	  This driver is for PCH(Platform controller Hub) GPIO of Intel Topcliff
 	  which is an IOH(Input/Output Hub) for x86 embedded processor.