Horus_fw changes for cnc shield

#ifdef CPU_MAP_ATMEGA328P_HORUS // Arduino Uno for Horus Project

  // Serial port pins
  #define SERIAL_RX USART_RX_vect
  #define SERIAL_UDRE USART_UDRE_vect

  // Define laser pulse output pins. NOTE: All laser pins must be on the same port.
  #define LASER_DDR       DDRB
  #define LASER_PORT      PORTB
  #define LASER1_BIT      1  // Uno Digital Pin 9
  #define LASER2_BIT      2  // Uno Digital Pin 10
  #define LASER3_BIT      3  // Uno Digital Pin 11
  #define LASER4_BIT      4  // Uno Digital Pin 12
  #define LASER_MASK      ((1<<LASER1_BIT)|(1<<LASER2_BIT)|(1<<LASER3_BIT)|(1<<LASER4_BIT)) // All step bits

  // Define step pulse output pins. NOTE: All step bit pins must be on the same port.
  #define STEP_DDR        DDRD
  #define STEP_PORT       PORTD
  #define X_STEP_BIT      2  // Uno Digital Pin 2
  #define Y_STEP_BIT      3  // Uno Digital Pin 3
  #define Z_STEP_BIT      4  // Uno Digital Pin 4
  #define STEP_MASK       ((1<<X_STEP_BIT)|(1<<Y_STEP_BIT)|(1<<Z_STEP_BIT)) // All step bits

  // Define step direction output pins. NOTE: All direction pins must be on the same port.
 #define DIRECTION_DDR     DDRD
  #define DIRECTION_PORT    PORTD
  #define X_DIRECTION_BIT   5  // Uno Digital Pin 5
  #define Y_DIRECTION_BIT   6  // Uno Digital Pin 6
  #define Z_DIRECTION_BIT   7  // Uno Digital Pin 7
  #define DIRECTION_MASK    ((1<<X_DIRECTION_BIT)|(1<<Y_DIRECTION_BIT)|(1<<Z_DIRECTION_BIT)) // All direction bits

  // Define stepper driver enable/disable output pin.
  #define STEPPERS_DISABLE_DDR    DDRB
  #define STEPPERS_DISABLE_PORT   PORTB
  #define STEPPERS_DISABLE_BIT    0  // Uno Digital Pin 8
  #define STEPPERS_DISABLE_MASK   (1<<STEPPERS_DISABLE_BIT)

  // Define probe switch input pin.
  #define PROBE_DDR       DDRC
  #define PROBE_PIN       PINC
  #define PROBE_PORT      PORTC
  #define PROBE_BIT       5  // Uno Analog Pin 5
  #define PROBE_MASK      (1<<PROBE_BIT)

#endif