dts: stm32n6: Disable axisram3

Those memories should be disabled by default and enabled
at application level.

Signed-off-by: Erwan Gouriou <[email protected]>

Author: erwango

dts/arm/st/n6/stm32n657X0.dtsi

@@ -22,7 +22,7 @@
 		ramcfg@42023100 {
 			axisram3: memory@34200000 {
 				reg = <0x34200000 DT_SIZE_K(448)>;
-				status = "okay";
+				status = "disabled";
 			};
 		};