px4fmu-v4:Board does CAN GPIO init

src/drivers/boards/px4fmu-v4/init.c

@@ -208,6 +208,10 @@ stm32_boardinitialize(void)
 	stm32_configgpio(GPIO_ADC1_IN4);	/* VDD_5V_SENS */
 	stm32_configgpio(GPIO_ADC1_IN11);	/* RSSI analog in */
 
+	// Configure CAN interface
+	stm32_configgpio(GPIO_CAN1_RX);
+	stm32_configgpio(GPIO_CAN1_TX);
+
 	// Configure power supply control/sense pins.
 	stm32_configgpio(GPIO_PERIPH_3V3_EN);
 	stm32_configgpio(GPIO_VDD_BRICK_VALID);