ARM: dts: stm32: Drop "u-boot-led" and "error-led" from stm32mp157a-dk1-u-boot

Remove obsolete properties "u-boot, u-boot-led" and "u-boot,error-led"
from stm32mp135f-dk-u-boot.dtsi.

Remove led-red which is now available in kernel DT.
See kernel series: https://patchwork.kernel.org/project/linux-arm-kernel/list/?series=1022570

Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
Reviewed-by: Quentin Schulz <quentin.schulz@cherry.de>

arch/arm/dts/stm32mp157a-dk1-u-boot.dtsi

@@ -15,8 +15,6 @@
 	};
 
 	config {
-		u-boot,boot-led = "led-blue";
-		u-boot,error-led = "led-red";
 		u-boot,mmc-env-partition = "fip";
 		st,adc_usb_pd = <&adc1 18>, <&adc1 19>;
 	};
@@ -68,9 +66,6 @@
 			/delete-property/label;
 		};
 
-		led-red {
-			gpios = <&gpioa 13 GPIO_ACTIVE_LOW>;
-		};
 	};
 };