[ARM] Wrap calls to descriptor handlers

This is part of Thomas Gleixner's generic IRQ patch, which converts
ARM to use the generic IRQ subsystem.  Here, we wrap calls to
desc->handler() in an inline function, desc_handle_irq().  This
reduces the size of Thomas' patch since the changes become more
localised.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mach-imx/irq.c b/arch/arm/mach-imx/irq.c
index 45d22dd..eeb8a6d 100644
--- a/arch/arm/mach-imx/irq.c
+++ b/arch/arm/mach-imx/irq.c
@@ -152,7 +152,7 @@
 	while (mask) {
 		if (mask & 1) {
 			DEBUG_IRQ("handling irq %d\n", irq);
-			desc->handle(irq, desc, regs);
+			desc_handle_irq(irq, desc, regs);
 		}
 		irq++;
 		desc++;