boards: st: stm32mp135f_dk: correct led_1 / led_2 polarity

blue and red leds polarity is ACTIVE_LOW hence correct the
DT to have them behave correctly.

Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>

Author: Alain Volmat

boards/st/stm32mp135f_dk/stm32mp135f_dk.dts

@@ -37,12 +37,12 @@
 		compatible = "gpio-leds";
 
 		blue_led_1: led_1 {
-			gpios = <&gpioa 14 GPIO_ACTIVE_HIGH>;
+			gpios = <&gpioa 14 GPIO_ACTIVE_LOW>;
 			label = "LD3";
 		};
 
 		red_led_2: led_2 {
-			gpios = <&gpioa 13 GPIO_ACTIVE_HIGH>;
+			gpios = <&gpioa 13 GPIO_ACTIVE_LOW>;
 			label = "LD4";
 		};
 	};