samples: pwm: Add overlay for nucleo_l4r5zi board

Add Devicetree overlay for sample drivers/led/pwm and fix the one in
basic/blinky_pwm for nucleo_l4r5zi board to set appropriate to enable
pwdleds and set appropriate timer prescaler.

Signed-off-by: Yishai Jaffe <[email protected]>

Author: yishai1999

samples/basic/blinky_pwm/boards/nucleo_l4r5zi.overlay

@@ -8,6 +8,10 @@
 	status = "okay";
 };
 
+&timers1 {
+	st,prescaler = <10000>;
+};
+
 &pwm1 {
 	status = "okay";
 };

samples/drivers/led/pwm/boards/nucleo_l4r5zi.overlay

@@ -0,0 +1,23 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Copyright (c) 2022 STMicroelectronics
+ */
+
+/ {
+	leds {
+		status = "disabled";
+	};
+};
+
+&pwmleds {
+	status = "okay";
+};
+
+&timers1 {
+	st,prescaler = <10000>;
+};
+
+&pwm1 {
+	status = "okay";
+};