boards: amd: versalnet_rpu: add TCM memory node

Add Tightly Coupled Memory (TCM) device tree node:
- Base address: 0x0
- Size: 64KB (0x10000)
- Compatible: mmio-sram

TCM provides low-latency memory access for R52 cores
and is essential for real-time applications.

Signed-off-by: Appana Durga Kedareswara rao <appana.durga.kedareswara.rao@amd.com>

boards/amd/versalnet_rpu/versalnet_rpu.dts

@@ -31,6 +31,11 @@
 		compatible = "mmio-sram";
 		reg = <0x30000 DT_SIZE_M(2047)>;
 	};
+
+	tcm: memory@0 {
+		compatible = "mmio-sram";
+		reg = <0x0 DT_SIZE_K(64)>;
+	};
 };
 
 &ocm {