dts: P5040DS: Add ESPI slave device node

Add ESPI slave node for P5040DS.
Signed-off-by: NXiaowei Bao <xiaowei.bao@nxp.com>
Signed-off-by: NHou Zhiqiang <Zhiqiang.Hou@nxp.com>
[Rebased]
Signed-off-by: NPriyanka Jain <priyanka.jain@nxp.com>

arch/powerpc/dts/p5040ds.dts

@@ -39,6 +39,7 @@
 		hydra_sg_slot6 = &hydra_sg_slot6;
 		hydra_xg_slot1 = &hydra_xg_slot1;
 		hydra_xg_slot2 = &hydra_xg_slot2;
+		spi0 = &espi0;
 	};
 
 	soc: soc@ffe000000 {
@@ -265,4 +266,16 @@
 	};
 };
 
+&espi0 {
+	status = "okay";
+	flash@0 {
+		compatible = "jedec,spi-nor";
+		#address-cells = <1>;
+		#size-cells = <1>;
+		reg = <0>;
+		/* input clock */
+		spi-max-frequency = <10000000>;
+	};
+};
+
 /include/ "p5040si-post.dtsi"