Added to #define for 1284/1284p Timer 3 inclusion.

ATmega1284/ATmega1284p have a 16 bit Timer 3 (not present in the ATmega644 and below).
Add to the #define to use Timer 3 or Timer 1 optionally.

Author: feilipu

libraries/Servo/src/avr/ServoTimers.h

@@ -47,7 +47,7 @@ typedef enum { _timer1, _Nbr_16timers } timer16_Sequence_t;
 #define _useTimer1
 typedef enum { _timer3, _timer1, _Nbr_16timers } timer16_Sequence_t;
 
-#elif defined(__AVR_ATmega128__) ||defined(__AVR_ATmega1281__)||defined(__AVR_ATmega2561__)
+#elif defined(__AVR_ATmega128__) || defined(__AVR_ATmega1281__) || defined(__AVR_ATmega1284__) || defined(__AVR_ATmega1284P__) || defined(__AVR_ATmega2561__)
 #define _useTimer3
 #define _useTimer1
 typedef enum { _timer3, _timer1, _Nbr_16timers } timer16_Sequence_t;