[nrf fromlist] dts: arm: nordic: nrf54l15 write block size

write-block-size correction.

Upstream PR: zephyrproject-rtos/zephyr#70412

Signed-off-by: Mateusz Michalek <mateusz.michalek@nordicsemi.no>

dts/arm/nordic/nrf54l_common.dtsi

@@ -18,7 +18,7 @@
 			rram0: rram@0 {
 				compatible = "soc-nv-flash";
 				erase-block-size = <4096>;
-				write-block-size = <1>;
+				write-block-size = <16>;
 			};
 		};
 	};