sh: Fix pcrel too far for in_nmi label.

Add lost in_nmi definition to solve pcrel too far.
Signed-off-by: Takashi YOSHII <takasi-y@ops.dti.ne.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/kernel/cpu/sh3/entry.S

@@ -320,6 +320,7 @@ skip_restore:
 
 	.align	2
 5:	.long	0x00001000	! DSP
+6:	.long	in_nmi
 7:	.long	0x30000000
 
 ! common exception handler