sh: Fix sh2a vbr table for more than 255 irqs

Signed-off-by: NPhil Edworthy <phil.edworthy@renesas.com>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

arch/sh/kernel/cpu/sh2a/ex.S

@@ -66,6 +66,7 @@ vector	=	0
 	.long	exception_entry0 + vector * 6
 vector	=	vector + 1
 	.endr
+vector	=	0
 	.rept	256
 	.long	exception_entry1 + vector * 6
 vector	=	vector + 1