Add my_led

apps/my_led/boards/black_f407ve.overlay

@@ -0,0 +1,21 @@
+/ {
+	custom_led0: custom_led0 {
+		compatible = "custom-led";
+		custom-gpios = <&gpioe 13 GPIO_ACTIVE_HIGH>;
+		my-delay-ms = <1000>; /* Optional, equals 500 by default */
+	};
+	aliases {
+		myled = &custom_led0;
+	};
+};
+
+&clk_hse {
+	clock-frequency = <DT_FREQ_M(25)>;
+};
+
+&pll {
+	div-m = <25>;
+	mul-n = <336>;
+	div-p = <2>;
+	div-q = <7>;
+};