Keyboard: Add Nyquist Rev 3 (#4287)

* Add Nyquist Rev 3

* Switch to split_common

keyboards/nyquist/rules.mk

@@ -1,8 +1,3 @@
-SRC += matrix.c \
-	   i2c.c \
-	   split_util.c \
-	   serial.c
-
 # MCU name
 #MCU = at90usb1287
 MCU = atmega32u4
@@ -41,9 +36,13 @@ F_USB = $(F_CPU)
 
 # Bootloader
 #     This definition is optional, and if your keyboard supports multiple bootloaders of
-#     different sizes, comment this out, and the correct address will be loaded 
+#     different sizes, comment this out, and the correct address will be loaded
 #     automatically (+60). See bootloader.mk for all options.
-BOOTLOADER = caterina
+ifeq ($(strip $(KEYBOARD)), nyquist/rev3)
+    BOOTLOADER = dfu
+else
+    BOOTLOADER = caterina
+endif
 
 # Interrupt driven control endpoint task(+60)
 OPT_DEFS += -DINTERRUPT_CONTROL_ENDPOINT
@@ -63,13 +62,10 @@ MIDI_ENABLE = no            # MIDI controls
 AUDIO_ENABLE = no           # Audio output on port C6
 UNICODE_ENABLE = no         # Unicode
 BLUETOOTH_ENABLE = no       # Enable Bluetooth with the Adafruit EZ-Key HID
-USE_I2C = yes
-RGBLIGHT_ENABLE = yes       # Enable WS2812 RGB underlight. 
+RGBLIGHT_ENABLE = yes       # Enable WS2812 RGB underlight.
 # Do not enable SLEEP_LED_ENABLE. it uses the same timer as BACKLIGHT_ENABLE
 SLEEP_LED_ENABLE = no    # Breathing sleep LED during USB suspend
 
-CUSTOM_MATRIX = yes
-
+SPLIT_KEYBOARD = yes
 LAYOUTS = ortho_5x12
-
 DEFAULT_FOLDER = nyquist/rev2