ARM: dts: Add 64MiB OpenBMC flash layout

This is an alternate layout used by OpenBMC systems

The division of space is as follows:

 u-boot + env: 0.5MB
 kernel/FIT: 5MB
 rofs: 42.5MB
 rwfs: 16MB

Signed-off-by: John Wang <wangzhiqiang.bj@bytedance.com>
Link: https://lore.kernel.org/r/20200929063955.1206-1-wangzhiqiang.bj@bytedance.com
Signed-off-by: Joel Stanley <joel@jms.id.au>

arch/arm/boot/dts/openbmc-flash-layout-64.dtsi

@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2020 Bytedance.
+ */
+
+partitions {
+	compatible = "fixed-partitions";
+	#address-cells = <1>;
+	#size-cells = <1>;
+
+	u-boot@0 {
+		reg = <0x0 0x60000>; // 384KB
+		label = "u-boot";
+	};
+
+	u-boot-env@e0000 {
+		reg = <0x60000 0x20000>; // 128KB
+		label = "u-boot-env";
+	};
+
+	kernel@100000 {
+		reg = <0x80000 0x500000>; // 5MB
+		label = "kernel";
+	};
+
+	rofs@a00000 {
+		reg = <0x580000 0x2a80000>; // 42.5MB
+		label = "rofs";
+	};
+
+	rwfs@6000000 {
+		reg = <0x3000000 0x1000000>; // 16MB
+		label = "rwfs";
+	};
+};