remove ESC uart define (#837)

Author: LYNHQQ

configs/HUMMINGBIRD_AIO255/config.h

@@ -84,7 +84,6 @@
 #define BARO_I2C_INSTANCE  I2CDEV_2
 #define MAG_I2C_INSTANCE   I2CDEV_2
 #define FLASH_SPI_INSTANCE SPI3
-#define ESC_SENSOR_UART    SERIAL_PORT_USART7
 #define DEFAULT_BLACKBOX_DEVICE BLACKBOX_DEVICE_FLASH
 #define DEFAULT_DSHOT_BITBANG DSHOT_BITBANG_ON
 #define DEFAULT_CURRENT_METER_SOURCE CURRENT_METER_ADC