update Servo library properties

Author: hathach

libraries/Servo/library.properties

@@ -6,4 +6,4 @@ sentence=Allows Arduino/Genuino boards to control a variety of servo motors.
 paragraph=This library can control a great number of servos.<br />It makes careful use of timers: the library can control 12 servos using only 1 timer.<br />On the Arduino Due you can control up to 60 servos.<br />
 category=Device Control
 url=http://www.arduino.cc/en/Reference/Servo
-architectures=avr,sam,samd,nrf52,stm32f4
+architectures=nrf52