ppc64: remove ppc_irq_dispatch_handler

Use __do_IRQ instead.  The only difference is that every controller
is now assumed to have an end() routine (only xics_8259 did not).

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
diff --git a/include/asm-powerpc/irq.h b/include/asm-powerpc/irq.h
index 2a768e0..225dc18 100644
--- a/include/asm-powerpc/irq.h
+++ b/include/asm-powerpc/irq.h
@@ -488,7 +488,7 @@
 
 extern void irq_ctx_init(void);
 extern void call_do_softirq(struct thread_info *tp);
-extern int call_ppc_irq_dispatch_handler(struct pt_regs *regs, int irq,
+extern int call___do_IRQ(int irq, struct pt_regs *regs,
 		struct thread_info *tp);
 
 #define __ARCH_HAS_DO_SOFTIRQ