powerpc: Add Microwatt device tree

Microwatt currently runs with MSR[HV] = 0, hence the usable-privilege
properties don't have bit 2 (for HV support) set, and we need the
/chosen/ibm,architecture-vec-5 property.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/YMwWkPcXlGDSQ9Q3@thinks.paulus.ozlabs.org

arch/powerpc/boot/dts/microwatt.dts

+/dts-v1/;
+
+/ {
+	#size-cells = <0x02>;
+	#address-cells = <0x02>;
+	model-name = "microwatt";
+	compatible = "microwatt-soc";
+
+	reserved-memory {
+		#size-cells = <0x02>;
+		#address-cells = <0x02>;
+		ranges;
+	};
+
+	memory@0 {
+		device_type = "memory";
+		reg = <0x00000000 0x00000000 0x00000000 0x10000000>;
+	};
+
+	cpus {
+		#size-cells = <0x00>;
+		#address-cells = <0x01>;
+
+		ibm,powerpc-cpu-features {
+			display-name = "Microwatt";
+			isa = <3000>;
+			device_type = "cpu-features";
+			compatible = "ibm,powerpc-cpu-features";
+
+			mmu-radix {
+				isa = <3000>;
+				usable-privilege = <2>;
+			};
+
+			little-endian {
+				isa = <2050>;
+				usable-privilege = <3>;
+				hwcap-bit-nr = <1>;
+			};
+
+			cache-inhibited-large-page {
+				isa = <2040>;
+				usable-privilege = <2>;
+			};
+
+			fixed-point-v3 {
+				isa = <3000>;
+				usable-privilege = <3>;
+			};
+
+			no-execute {
+				isa = <2010>;
+				usable-privilege = <2>;
+			};
+
+			floating-point {
+				hwcap-bit-nr = <27>;
+				isa = <0>;
+				usable-privilege = <3>;
+			};
+		};
+
+		PowerPC,Microwatt@0 {
+			i-cache-sets = <2>;
+			ibm,dec-bits = <64>;
+			reservation-granule-size = <64>;
+			clock-frequency = <100000000>;
+			timebase-frequency = <100000000>;
+			i-tlb-sets = <1>;
+			ibm,ppc-interrupt-server#s = <0>;
+			i-cache-block-size = <64>;
+			d-cache-block-size = <64>;
+			d-cache-sets = <2>;
+			i-tlb-size = <64>;
+			cpu-version = <0x990000>;
+			status = "okay";
+			i-cache-size = <0x1000>;
+			ibm,processor-radix-AP-encodings = <0x0c 0xa0000010 0x20000015 0x4000001e>;
+			tlb-size = <0>;
+			tlb-sets = <0>;
+			device_type = "cpu";
+			d-tlb-size = <128>;
+			d-tlb-sets = <2>;
+			reg = <0>;
+			general-purpose;
+			64-bit;
+			d-cache-size = <0x1000>;
+			ibm,chip-id = <0>;
+		};
+	};
+
+	chosen {
+		bootargs = "";
+		ibm,architecture-vec-5 = [19 00 10 00 00 00 00 00 00 00 00 00 00 00 00 00
+					  00 00 00 00 00 00 00 00 40 00 40];
+	};
+
+};