wl12xx: remove duplicated include from main.c

Remove duplicated include.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Luciano Coelho <luca@coelho.fi>

drivers/net/wireless/ti/wl12xx/main.c

@@ -32,7 +32,6 @@
 #include "../wlcore/acx.h"
 #include "../wlcore/tx.h"
 #include "../wlcore/rx.h"
-#include "../wlcore/io.h"
 #include "../wlcore/boot.h"
 
 #include "wl12xx.h"