ARM: dts: microchip: sama7g5: Add cache configuration for cpu node

Describe the cache memories according with datasheet chapter 15.2:

- L1 cache configuration with 32KB for both data and instruction cache.
- L2 cache configuration with 256KB unified cache.

Before this patch the kernel reported the warning:

[    0.171425] cacheinfo: Unable to detect cache hierarchy for CPU 0

Signed-off-by: Mihai Sain <mihai.sain@microchip.com>
Link: https://lore.kernel.org/r/20250619070636.8844-3-mihai.sain@microchip.com
Signed-off-by: Claudiu Beznea <claudiu.beznea@tuxon.dev>

Author: Mihai Sain

arch/arm/boot/dts/microchip/sama7g5.dtsi

@@ -38,6 +38,16 @@
 			clock-names = "cpu";
 			operating-points-v2 = <&cpu_opp_table>;
 			#cooling-cells = <2>; /* min followed by max */
+			d-cache-size = <0x8000>;	// L1, 32 KB
+			i-cache-size = <0x8000>;	// L1, 32 KB
+			next-level-cache = <&L2>;
+
+			L2: l2-cache {
+				compatible = "cache";
+				cache-level = <2>;
+				cache-size = <0x40000>; // L2, 256 KB
+				cache-unified;
+			};
 		};
 	};