[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>

include/asm-arm/mach/irq.h

@@ -91,6 +91,14 @@ struct irqdesc {
 
 extern struct irqdesc irq_desc[];
 
+/*
+ * Helpful inline function for calling irq descriptor handlers.
+ */
+static inline void desc_handle_irq(unsigned int irq, struct irqdesc *desc, struct pt_regs *regs)
+{
+	desc->handle(irq, desc, regs);
+}
+
 /*
  * This is internal.  Do not use it.
  */