[nrf fromlist] tests: drivers: counter: Enable test execution on nRF54L20pdk

Add overlay needed to execute counter tests on nRF54L20pdk.

Upstream PR #: 82968

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

Author: nordic-segl

tests/drivers/counter/counter_basic_api/boards/nrf54l20pdk_nrf54l20_cpuapp.overlay

@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2024 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+&timer00 {
+	prescaler = <6>;
+	status = "okay";
+};
+
+&timer10 {
+	prescaler = <4>;
+	status = "okay";
+};
+
+&timer20 {
+	prescaler = <4>;
+	status = "okay";
+};
+
+&timer21 {
+	prescaler = <4>;
+	status = "okay";
+};
+
+&timer22 {
+	prescaler = <4>;
+	status = "okay";
+};
+
+&timer23 {
+	prescaler = <4>;
+	status = "okay";
+};
+
+&timer24 {
+	prescaler = <4>;
+	status = "okay";
+};