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: NKevin Hilman <khilman@ti.com>

arch/arm/plat-omap/Kconfig

@@ -13,6 +13,7 @@ config ARCH_OMAP1
 	bool "TI OMAP1"
 	select CLKDEV_LOOKUP
 	select CLKSRC_MMIO
+	select GENERIC_IRQ_CHIP
 	help
 	  "Systems based on omap7xx, omap15xx or omap16xx"