boards: st: fix STM32WB0 boards DTS files coding style

Fix board DTS coding style issues to prevent they spread when a	new
board is introduced and used this DTS as example start point.

Issues addressed from Zephyr devicetree style guidelines [1]:
- Insert a single empty line to separate nodes at the same hierarchy level.

No functional change.

Link: https://docs.zephyrproject.org/latest/contribute/style/devicetree.html [1]
Signed-off-by: Etienne Carriere <etienne.carriere@st.com>

Author: etienne-lms

boards/st/nucleo_wb05kz/nucleo_wb05kz.dts

@@ -28,12 +28,15 @@
 
 	leds: leds {
 		compatible ="gpio-leds";
+
 		blue_led_1: led_0 {
 			gpios = <&gpiob 1 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>;
 		};
+
 		green_led_1: led_1 {
 			gpios = <&gpiob 4 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>;
 		};
+
 		red_led_1: led_2 {
 			gpios = <&gpiob 2 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>;
 		};
@@ -42,23 +45,27 @@
 	pwmleds: pwmleds {
 		compatible = "pwm-leds";
 		status = "okay";
+
 		pwm_red_led_1: pwm_led_1 {
 			pwms = <&pwm2 3 PWM_MSEC(20) PWM_POLARITY_NORMAL>;
 		};
 	};
 
 	gpio_keys {
 		compatible = "gpio-keys";
+
 		user_button_1: button_0 {
 			label = "SW1";
 			gpios = <&gpioa 0 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>;
 			zephyr,code = <INPUT_KEY_0>;
 		};
+
 		user_button_2: button_1 {
 			label = "SW2";
 			gpios = <&gpiob 5 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>;
 			zephyr,code = <INPUT_KEY_1>;
 		};
+
 		user_button_3: button_2 {
 			label = "SW3";
 			gpios = <&gpiob 14 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>;
@@ -165,6 +172,7 @@
 		compatible = "fixed-partitions";
 		#address-cells = <1>;
 		#size-cells = <1>;
+
 		/* Set 8KB of storage at the end of 192KB flash */
 		storage_partition: partition@2e000 {
 			label = "storage";

boards/st/nucleo_wb07cc/nucleo_wb07cc.dts

@@ -28,36 +28,43 @@
 
 	leds: leds {
 		compatible ="gpio-leds";
+
 		blue_led_1: led_0 {
 			gpios = <&gpiob 0 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>;
 		};
+
 		green_led_1: led_1 {
 			gpios = <&gpiob 4 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>;
 		};
+
 		red_led_1: led_2 {
 			gpios = <&gpiob 2 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>;
 		};
 	};
 
 	pwmleds: pwmleds {
 		compatible = "pwm-leds";
+
 		pwm_red_led_1: pwm_red_led_1 {
 			pwms = <&pwm1 3 PWM_MSEC(20) PWM_POLARITY_NORMAL>;
 		};
 	};
 
 	gpio_keys {
 		compatible = "gpio-keys";
+
 		user_button_1: button_0 {
 			label = "SW1";
 			gpios = <&gpioa 0 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>;
 			zephyr,code = <INPUT_KEY_0>;
 		};
+
 		user_button_2: button_1 {
 			label = "SW2";
 			gpios = <&gpiob 5 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>;
 			zephyr,code = <INPUT_KEY_1>;
 		};
+
 		user_button_3: button_2 {
 			label = "SW3";
 			gpios = <&gpiob 9 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>;
@@ -162,6 +169,7 @@
 		compatible = "fixed-partitions";
 		#address-cells = <1>;
 		#size-cells = <1>;
+
 		/* Set aside 16KB of storage at the end of 256KB flash */
 		storage_partition: partition@3c000 {
 			label = "storage";

boards/st/nucleo_wb09ke/nucleo_wb09ke.dts

@@ -28,12 +28,15 @@
 
 	leds: leds {
 		compatible ="gpio-leds";
+
 		blue_led_1: led_0 {
 			gpios = <&gpiob 1 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>;
 		};
+
 		green_led_1: led_1 {
 			gpios = <&gpiob 4 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>;
 		};
+
 		red_led_1: led_2 {
 			gpios = <&gpiob 2 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>;
 		};
@@ -42,23 +45,27 @@
 	pwmleds: pwmleds {
 		compatible = "pwm-leds";
 		status = "okay";
+
 		pwm_red_led_1: pwm_led_1 {
 			pwms = <&pwm2 3 PWM_MSEC(20) PWM_POLARITY_NORMAL>;
 		};
 	};
 
 	gpio_keys {
 		compatible = "gpio-keys";
+
 		user_button_1: button_0 {
 			label = "SW1";
 			gpios = <&gpioa 0 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>;
 			zephyr,code = <INPUT_KEY_0>;
 		};
+
 		user_button_2: button_1 {
 			label = "SW2";
 			gpios = <&gpiob 5 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>;
 			zephyr,code = <INPUT_KEY_1>;
 		};
+
 		user_button_3: button_2 {
 			label = "SW3";
 			gpios = <&gpiob 14 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>;
@@ -164,6 +171,7 @@
 		compatible = "fixed-partitions";
 		#address-cells = <1>;
 		#size-cells = <1>;
+
 		/* Set 32KB of storage at the end of 512KB flash */
 		storage_partition: partition@78000 {
 			label = "storage";