powerpc/of: add eSPI controller dts bindings and DTS modification

Also modifiy the document of cell-index in SPI controller. Add the
SPI flash(s25fl128p01) support on p4080ds and mpc8536ds board.

Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
diff --git a/arch/powerpc/boot/dts/mpc8536ds.dts b/arch/powerpc/boot/dts/mpc8536ds.dts
index 815cebb..a75c10e 100644
--- a/arch/powerpc/boot/dts/mpc8536ds.dts
+++ b/arch/powerpc/boot/dts/mpc8536ds.dts
@@ -108,6 +108,58 @@
 			};
 		};
 
+		spi@7000 {
+			#address-cells = <1>;
+			#size-cells = <0>;
+			compatible = "fsl,mpc8536-espi";
+			reg = <0x7000 0x1000>;
+			interrupts = <59 0x2>;
+			interrupt-parent = <&mpic>;
+			fsl,espi-num-chipselects = <4>;
+
+			flash@0 {
+				#address-cells = <1>;
+				#size-cells = <1>;
+				compatible = "spansion,s25sl12801";
+				reg = <0>;
+				spi-max-frequency = <40000000>;
+				partition@u-boot {
+					label = "u-boot";
+					reg = <0x00000000 0x00100000>;
+					read-only;
+				};
+				partition@kernel {
+					label = "kernel";
+					reg = <0x00100000 0x00500000>;
+					read-only;
+				};
+				partition@dtb {
+					label = "dtb";
+					reg = <0x00600000 0x00100000>;
+					read-only;
+				};
+				partition@fs {
+					label = "file system";
+					reg = <0x00700000 0x00900000>;
+				};
+			};
+			flash@1 {
+				compatible = "spansion,s25sl12801";
+				reg = <1>;
+				spi-max-frequency = <40000000>;
+			};
+			flash@2 {
+				compatible = "spansion,s25sl12801";
+				reg = <2>;
+				spi-max-frequency = <40000000>;
+			};
+			flash@3 {
+				compatible = "spansion,s25sl12801";
+				reg = <3>;
+				spi-max-frequency = <40000000>;
+			};
+		};
+
 		dma@21300 {
 			#address-cells = <1>;
 			#size-cells = <1>;