mips: octeon: Add misc remaining header files

Import misc remaining header files from 2013 U-Boot. These will be used
by the later added drivers to support PCIe and networking on the MIPS
Octeon II / III platforms.

Signed-off-by: Aaron Williams <awilliams@marvell.com>
Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Aaron Williams <awilliams@marvell.com>
Cc: Chandrakala Chavva <cchavva@marvell.com>
Cc: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>

arch/mips/mach-octeon/include/mach/cvmx-gmx.h

@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020 Marvell International Ltd.
+ *
+ * Interface to the GMX hardware.
+ */
+
+#ifndef __CVMX_GMX_H__
+#define __CVMX_GMX_H__
+
+/* CSR typedefs have been moved to cvmx-gmx-defs.h */
+
+int cvmx_gmx_set_backpressure_override(u32 interface, u32 port_mask);
+int cvmx_agl_set_backpressure_override(u32 interface, u32 port_mask);
+
+#endif