cavium: Add CN81xx SoC and eval board support

This adds Cavium CN81xx SoC and SFF EVB files.

Code is based off of Cavium's Octeon-TX SDK:
https://github.com/Cavium-Open-Source-Distributions/OCTEON-TX-SDK

BDK coreboot differences:
bootblock:
- Get rid of BDK header
- Add Kconfig for link address
- Move CAR setup code into assembly
- Move unaligned memory access enable into assembly
- Implement custom bootblock entry function
- Add CLIB and CSIB blobs

romstage:
- Use minimal DRAM init only

devicetree:
- Convert FTD to static C file containing key value pairs

Tested on CN81xx:
- Boots to payload
- Tested with GNU/Linux 4.16.3
- All hardware is usable (after applying additional commits)

Implemented in future commits:
- Vboot integration
- MMU suuport
- L2 Cache handling
- ATF from external repo
- Devicetree patching
- Extended DRAM testing
- UART init

Not working:
- Booting a payload
- Booting upstream ATF

TODO:
- Configuration straps

Change-Id: I47b4412d29203b45aee49bfa026c1d86ef7ce688
Signed-off-by: David Hendricks <dhendricks@fb.com>
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/23037
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: David Hendricks <david.hendricks@gmail.com>
diff --git a/src/soc/cavium/cn81xx/cpu.c b/src/soc/cavium/cn81xx/cpu.c
new file mode 100644
index 0000000..c054aa8
--- /dev/null
+++ b/src/soc/cavium/cn81xx/cpu.c
@@ -0,0 +1,26 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2018-present  Facebook, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that 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.
+ */
+
+#include <types.h>
+#include <arch/io.h>
+#include <soc/cpu.h>
+#include <bdk-coreboot.h>
+
+/* Return the number of cores available in the chip */
+size_t cpu_get_num_cores(void)
+{
+	uint64_t available = read64((void *)0x87e006001738ll);
+	return bdk_dpop(available);
+}