ARM: UniPhier: replace <asm/io.h> with <linux/io.h>

In the Linux coding style, it is recommended to include <linux/io.h>
rather than <asm/io.h>.  Follow this trend.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/drivers/usb/host/ehci-uniphier.c b/drivers/usb/host/ehci-uniphier.c
index 846bf50..c3f827c 100644
--- a/drivers/usb/host/ehci-uniphier.c
+++ b/drivers/usb/host/ehci-uniphier.c
@@ -1,14 +1,12 @@
 /*
- * Copyright (C) 2014 Panasonic Corporation
- * Copyright (C) 2015 Socionext Inc.
- *   Author: Masahiro Yamada <yamada.masahiro@socionext.com>
+ * Copyright (C) 2014-2015 Masahiro Yamada <yamada.masahiro@socionext.com>
  *
  * SPDX-License-Identifier:	GPL-2.0+
  */
 
 #include <common.h>
 #include <linux/err.h>
-#include <asm/io.h>
+#include <linux/io.h>
 #include <usb.h>
 #include <mach/mio-regs.h>
 #include <fdtdec.h>