OMAP1: enable GENERIC_IRQ_CHIP

OMAP1 needs this also since GPIO driver (common for all OMAPs) is
being converted to use generic IRQ chip.

Signed-off-by: Kevin Hilman <khilman@ti.com>
diff --git a/arch/arm/plat-omap/Kconfig b/arch/arm/plat-omap/Kconfig
index 6e6735f..bb8f4a6 100644
--- a/arch/arm/plat-omap/Kconfig
+++ b/arch/arm/plat-omap/Kconfig
@@ -13,6 +13,7 @@
 	bool "TI OMAP1"
 	select CLKDEV_LOOKUP
 	select CLKSRC_MMIO
+	select GENERIC_IRQ_CHIP
 	help
 	  "Systems based on omap7xx, omap15xx or omap16xx"