tests: drivers: pwm: pwm_api: add support for nucleo_h753zi

add .overlay file with timers1 node configuration.

Signed-off-by: Fabrice DJIATSA <[email protected]>

Author: djiatsaf-st

tests/drivers/pwm/pwm_api/boards/nucleo_h753zi.overlay

@@ -0,0 +1,9 @@
+/*
+ * Copyright (c) 2025 STMicroelectronics
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+&timers1 {
+	st,prescaler = <10000>;
+};