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/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S
index 9d09f0a..ae48a00 100644
--- a/arch/powerpc/kernel/misc_64.S
+++ b/arch/powerpc/kernel/misc_64.S
@@ -89,12 +89,12 @@
 	mtlr	r0
 	blr
 
-_GLOBAL(call_ppc_irq_dispatch_handler)
+_GLOBAL(call___do_IRQ)
 	mflr	r0
 	std	r0,16(r1)
 	stdu	r1,THREAD_SIZE-112(r5)
 	mr	r1,r5
-	bl	.ppc_irq_dispatch_handler
+	bl	.__do_IRQ
 	ld	r1,0(r1)
 	ld	r0,16(r1)
 	mtlr	r0