Add LED define, for IRremote

teensy4/core_pins.h

@@ -370,6 +370,8 @@
 #define CORE_PIN32_PADCONFIG	IOMUXC_SW_PAD_CTL_PAD_GPIO_B0_12
 #define CORE_PIN33_PADCONFIG	IOMUXC_SW_PAD_CTL_PAD_GPIO_EMC_08
 
+#define CORE_LED0_PIN		13
+
 #define CORE_ADC0_PIN		14
 #define CORE_ADC1_PIN		15
 #define CORE_ADC2_PIN		16