ARM: omap1: Switch to use MULTI_IRQ

This allows us to get a bit further with SPARSE_IRQ and
MULTIARCH support.

Note that we now also rename omap_irq_flags to omap_l2_irq
as that's the omap_irq_flags naming is confusing. It just
contains the interrupt number for the l2 irq.

Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Tony Lindgren <tony@atomide.com>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 45df48b..881a76c 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -752,6 +752,7 @@
 	select GENERIC_IRQ_CHIP
 	select HAVE_IDE
 	select IRQ_DOMAIN
+	select MULTI_IRQ_HANDLER
 	select NEED_MACH_IO_H if PCCARD
 	select NEED_MACH_MEMORY_H
 	help