[MIPS] do_IRQ cleanup

Now we have both function and macro version of do_IRQ() and the former
is used only by DEC and non-preemptive kernel.  This patch makes
everyone use the macro version and removes the function version.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/dec/int-handler.S b/arch/mips/dec/int-handler.S
index 31dd47d..b251ef8 100644
--- a/arch/mips/dec/int-handler.S
+++ b/arch/mips/dec/int-handler.S
@@ -267,7 +267,7 @@
 		LONG_L	s0, TI_REGS($28)
 		LONG_S	sp, TI_REGS($28)
 		PTR_LA	ra, ret_from_irq
-		j	do_IRQ
+		j	dec_irq_dispatch
 		 nop
 
 #ifdef CONFIG_32BIT