sh: remove duplicated #include

Remove duplicated #include('s) in
  arch/sh/kernel/cpu/sh4a/clock-sh7786.c
Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/kernel/cpu/sh4a/clock-sh7786.c

@@ -13,7 +13,6 @@
 #include <linux/kernel.h>
 #include <linux/clk.h>
 #include <linux/io.h>
-#include <linux/clk.h>
 #include <asm/clkdev.h>
 #include <asm/clock.h>
 #include <asm/freq.h>