powerpc: Enable device tree support for P2020RDB

Add device tree for P1020RDB boards and enable CONFIG_OF_CONTROL
so that device tree can be compiled.
Update board README for device tree usage.

Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
Reviewed-by: Prabhakar Kushwaha <prabhakar.kushwaha@nxp.com>
diff --git a/arch/powerpc/dts/Makefile b/arch/powerpc/dts/Makefile
index 3a806bd..bee1e2d 100644
--- a/arch/powerpc/dts/Makefile
+++ b/arch/powerpc/dts/Makefile
@@ -2,6 +2,7 @@
 
 dtb-$(CONFIG_TARGET_P1020RDB_PC) += p1020rdb-pc.dtb p1020rdb-pc_36b.dtb
 dtb-$(CONFIG_TARGET_P1020RDB_PD) += p1020rdb-pd.dtb
+dtb-$(CONFIG_TARGET_P2020RDB) += p2020rdb-pc.dtb p2020rdb-pc_36b.dtb
 dtb-$(CONFIG_TARGET_T1024RDB) += t1024rdb.dtb
 dtb-$(CONFIG_TARGET_T1042D4RDB) += t1042d4rdb.dtb
 dtb-$(CONFIG_TARGET_T2080QDS) += t2080qds.dtb
diff --git a/arch/powerpc/dts/p2020-post.dtsi b/arch/powerpc/dts/p2020-post.dtsi
new file mode 100644
index 0000000..f20d1fa
--- /dev/null
+++ b/arch/powerpc/dts/p2020-post.dtsi
@@ -0,0 +1,27 @@
+// SPDX-License-Identifier: GPL-2.0+ OR X11
+/*
+ * P2020 Silicon/SoC Device Tree Source (post include)
+ *
+ * Copyright 2013 Freescale Semiconductor Inc.
+ * Copyright 2019 NXP
+ */
+
+&soc {
+	#address-cells = <1>;
+	#size-cells = <1>;
+	device_type = "soc";
+	compatible = "fsl,p2020-immr", "simple-bus";
+	bus-frequency = <0x0>;
+
+	mpic: pic@40000 {
+		interrupt-controller;
+		#address-cells = <0>;
+		#interrupt-cells = <4>;
+		reg = <0x40000 0x40000>;
+		compatible = "fsl,mpic";
+		device_type = "open-pic";
+		big-endian;
+		single-cpu-affinity;
+		last-interrupt-source = <255>;
+	};
+};
diff --git a/arch/powerpc/dts/p2020.dtsi b/arch/powerpc/dts/p2020.dtsi
new file mode 100644
index 0000000..7c4c206
--- /dev/null
+++ b/arch/powerpc/dts/p2020.dtsi
@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: GPL-2.0+ OR X11
+/*
+ * P2020 Silicon/SoC Device Tree Source (pre include)
+ *
+ * Copyright 2013 Freescale Semiconductor Inc.
+ * Copyright 2019 NXP
+ */
+
+/dts-v1/;
+
+/include/ "e500v2_power_isa.dtsi"
+
+/ {
+	#address-cells = <2>;
+	#size-cells = <2>;
+	interrupt-parent = <&mpic>;
+
+	cpus {
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		cpu0: PowerPC,P2020@0 {
+			device_type = "cpu";
+			reg = <0>;
+		};
+		cpu1: PowerPC,P2020@1 {
+			device_type = "cpu";
+			reg = <1>;
+		};
+	};
+};
diff --git a/arch/powerpc/dts/p2020rdb-pc.dts b/arch/powerpc/dts/p2020rdb-pc.dts
new file mode 100644
index 0000000..4800b76
--- /dev/null
+++ b/arch/powerpc/dts/p2020rdb-pc.dts
@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: GPL-2.0+ OR X11
+/*
+ * P2020RDB-PC Device Tree Source
+ *
+ * Copyright 2013 - 2015 Freescale Semiconductor Inc.
+ * Copyright 2019 NXP
+ */
+
+/include/ "p2020.dtsi"
+
+/ {
+	model = "fsl,P2020RDB-PC";
+	compatible = "fsl,P2020RDB-PC";
+	#address-cells = <2>;
+	#size-cells = <2>;
+	interrupt-parent = <&mpic>;
+
+	soc: soc@ffe00000 {
+		ranges = <0x0 0x0 0xffe00000 0x100000>;
+	};
+};
+
+/include/ "p2020-post.dtsi"
diff --git a/arch/powerpc/dts/p2020rdb-pc_36b.dts b/arch/powerpc/dts/p2020rdb-pc_36b.dts
new file mode 100644
index 0000000..8323b90
--- /dev/null
+++ b/arch/powerpc/dts/p2020rdb-pc_36b.dts
@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: GPL-2.0+ OR X11
+/*
+ * P2020RDB-PC (36-bit address map) Device Tree Source
+ *
+ * Copyright 2013 - 2015 Freescale Semiconductor Inc.
+ * Copyright 2019 NXP
+ */
+
+/include/ "p2020.dtsi"
+
+/ {
+	model = "fsl,P2020RDB-PC";
+	compatible = "fsl,P2020RDB-PC";
+	#address-cells = <2>;
+	#size-cells = <2>;
+	interrupt-parent = <&mpic>;
+
+	soc: soc@fffe00000 {
+		ranges = <0x0 0xf 0xffe00000 0x100000>;
+	};
+};
+
+/include/ "p2020-post.dtsi"