[nrf fromlist] boards: nordic: nrf54lm20dk: Extend ext memory node with reset timing

Extend external memory node with properties that configure
reset pin and reset pulse timing.

Signed-off-by: Sebastian Głąb <[email protected]>

Author: nordic-segl

boards/nordic/nrf54lm20dk/nrf54lm20a_cpuapp_common.dtsi

@@ -166,5 +166,8 @@ zephyr_udc0: &usbhs {
 		has-dpd;
 		t-enter-dpd = <10000>;
 		t-exit-dpd = <35000>;
+		reset-gpios = <&gpio2 0 GPIO_ACTIVE_LOW>;
+		/* t-reset-pulse = <10000>; */
+		/* t-reset-recovery = <35000>; */
 	};
 };