ARM: dts: aspeed: ast2600evb: Use custom flash layout

The AST2600 u-boot and kernel images have outgrown the OpenBMC layout.
While BMC machines use 128MB SPI NOR chips, we only have 64MB on the EVB
so use a layout that has a smaller region for the ro and rw filesystems.
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>

arch/arm/boot/dts/aspeed-ast2600-evb.dts

@@ -92,7 +92,37 @@ flash@0 {
 		m25p,fast-read;
 		label = "bmc";
 		spi-max-frequency = <50000000>;
-#include "openbmc-flash-layout.dtsi"
+
+		partitions {
+			compatible = "fixed-partitions";
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			u-boot@0 {
+				reg = <0x0 0xe0000>; // 896KB
+				label = "u-boot";
+			};
+
+			u-boot-env@e0000 {
+				reg = <0xe0000 0x20000>; // 128KB
+				label = "u-boot-env";
+			};
+
+			kernel@100000 {
+				reg = <0x100000 0x900000>; // 9MB
+				label = "kernel";
+			};
+
+			rofs@a00000 {
+				reg = <0xa00000 0x2000000>; // 32MB
+				label = "rofs";
+			};
+
+			rwfs@6000000 {
+				reg = <0x2a00000 0x1600000>; // 22MB
+				label = "rwfs";
+			};
+		};
 	};
 };