arm64: dts: ti: k3-j721e-sk: Describe OSPI flash partition info

Describe OSPI flash partition information through device tree, this
helps to remove passing partition information through the mtdparts
commandline parameter which requires maintaining the partition
information in a string format. J721E SK has a S28 64 MiB OSPI flash
with sector size of 256 KiB thus the size of the smallest partition is
chosen as 256 KiB, the partition names and offsets are chosen according
to the corresponding name and offsets in bootloader.
Signed-off-by: Vaishnav Achath <vaishnav.a@ti.com>
Link: https://lore.kernel.org/r/20230513141712.27346-3-vaishnav.a@ti.comSigned-off-by: Vignesh Raghavendra <vigneshr@ti.com>

arch/arm64/boot/dts/ti/k3-j721e-sk.dts

@@ -568,6 +568,52 @@ flash@0 {
 		cdns,tchsh-ns = <60>;
 		cdns,tslch-ns = <60>;
 		cdns,read-delay = <4>;
+
+		partitions {
+			compatible = "fixed-partitions";
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			partition@0 {
+				label = "ospi.tiboot3";
+				reg = <0x0 0x80000>;
+			};
+
+			partition@80000 {
+				label = "ospi.tispl";
+				reg = <0x80000 0x200000>;
+			};
+
+			partition@280000 {
+				label = "ospi.u-boot";
+				reg = <0x280000 0x400000>;
+			};
+
+			partition@680000 {
+				label = "ospi.env";
+				reg = <0x680000 0x40000>;
+			};
+
+			partition@6c0000 {
+				label = "ospi.sysfw";
+				reg = <0x6c0000 0x100000>;
+			};
+
+			partition@7c0000 {
+				label = "ospi.env.backup";
+				reg = <0x7c0000 0x40000>;
+			};
+
+			partition@800000 {
+				label = "ospi.rootfs";
+				reg = <0x800000 0x37c0000>;
+			};
+
+			partition@3fc0000 {
+				label = "ospi.phypattern";
+				reg = <0x3fc0000 0x40000>;
+			};
+		};
 	};
 };