Staging: rtl8192u - changed include of asm/io.h

Changed include of <asm/io.h> to be <linux/io.h>
Complies, but I don't have hardware.
Found using checkpatch.
Signed-off-by: NDerek Robson <robsonde@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8192u/r8192U.h

@@ -34,7 +34,7 @@
 #include <linux/proc_fs.h>
 #include <linux/if_arp.h>
 #include <linux/random.h>
-#include <asm/io.h>
+#include <linux/io.h>
 #include "ieee80211/ieee80211.h"
 
 #define RTL8192U