sh: Add netdev header fixing of warning/build

Signed-off-by: Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com>
Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>

cpu/sh4/cpu.c

@@ -23,6 +23,7 @@
 
 #include <common.h>
 #include <command.h>
+#include <netdev.h>
 #include <asm/processor.h>
 #include <asm/cache.h>