arc: add architecture header files

These are header files used by ARC700 architecture.

Also note that "arch-arc700/hardware.h" is only required for compilation of
"designware_i2c" driver which refers to "asm/arch/hardware.h".
It would be good to fix mentioned driver sometime soon but it will cause
changes in ARM board configs that use "designware_i2c".

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>

Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Francois Bedard <fbedard@synopsys.com>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Heiko Schocher <hs@denx.de>
diff --git a/arch/arc/include/asm/byteorder.h b/arch/arc/include/asm/byteorder.h
new file mode 100644
index 0000000..2fa9776
--- /dev/null
+++ b/arch/arc/include/asm/byteorder.h
@@ -0,0 +1,23 @@
+/*
+ * Copyright (C) 2013-2014 Synopsys, Inc. All rights reserved.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef __ASM_ARC_BYTEORDER_H
+#define __ASM_ARC_BYTEORDER_H
+
+#include <asm/types.h>
+
+#if defined(__GNUC__) && !defined(__STRICT_ANSI__)
+	#define __BYTEORDER_HAS_U64__
+	#define __SWAB_64_THRU_32__
+#endif
+
+#ifdef __LITTLE_ENDIAN__
+	#include <linux/byteorder/little_endian.h>
+#else
+	#include <linux/byteorder/big_endian.h>
+#endif	/* CONFIG_SYS_BIG_ENDIAN */
+
+#endif	/* ASM_ARC_BYTEORDER_H */