bcm968580xref: add initial support

This add the initial support of the broadcom reference
board bcm968580xref with a bcm6858 SoC.

This board has 512 MB of ram, 256 MB of flash (nand),
2 usb port, 1 uart, 4 ethernet ports (LAN), 1 ethernet port (WAN).

Signed-off-by: Philippe Reynes <philippe.reynes@softathome.com>
diff --git a/arch/arm/dts/bcm968580xref.dts b/arch/arm/dts/bcm968580xref.dts
new file mode 100644
index 0000000..0c59f94
--- /dev/null
+++ b/arch/arm/dts/bcm968580xref.dts
@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2018 Philippe Reynes <philippe.reynes@softathome.com>
+ */
+
+/dts-v1/;
+
+#include "bcm6858.dtsi"
+
+/ {
+	model = "Broadcom bcm68580xref";
+	compatible = "broadcom,bcm68580xref", "brcm,bcm6858";
+
+	aliases {
+		serial0 = &uart0;
+	};
+
+	chosen {
+		stdout-path = "serial0:115200n8";
+	};
+
+	memory {
+		device_type = "memory";
+		reg = <0x0 0x0 0x0 0x20000000>;
+	};
+};
+
+&uart0 {
+	u-boot,dm-pre-reloc;
+	status = "okay";
+};