tests: benchmarks: mulicore: idle_spim: Align idle_spim tests

Add configuration to idle_spim test for the device runtime PM.

Signed-off-by: Adam Kondraciuk <[email protected]>

Author: adamkondraciuk

tests/benchmarks/multicore/idle_spim/boards/nrf54h20dk_nrf54h20_cpuapp.overlay

@@ -0,0 +1,13 @@
+/*
+ * Copyright (c) 2024 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
+ */
+
+&spi131 {
+	zephyr,pm-device-runtime-auto;
+};
+
+&exmif {
+	status = "disabled";
+};