arch/sh/boards/mach-se/7343/irq.c: removed duplicated #include

Removed duplicated include <linux/irq.h> in
arch/sh/boards/mach-se/7343/irq.c.

Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>