ARM: tegra: move tegra-ahb.h out of arch/arm/mach-tegra/

We wish to empty arch/arm/mach-tegra/include/mach/ as much as possible
to enable single zImage. Move tegra-ahb.h to a more central location
(suggested by Arnd, OK'd by Greg KH), and actually make tegra-ahb.c
include the header to ensure client and provider agree on the prototype.

Signed-off-by: Stephen Warren <swarren@nvidia.com>

include/linux/tegra-ahb.h

@@ -0,0 +1,19 @@
+/*
+ * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+
+#ifndef __LINUX_AHB_H__
+#define __LINUX_AHB_H__
+
+extern int tegra_ahb_enable_smmu(struct device_node *ahb);
+
+#endif	/* __LINUX_AHB_H__ */