[Keyboard] Minivan : add missing enable to support RGB LEDs (#13157)

Config.h has support for RGB LEDs but enable line was missing in rules.mk

keyboards/thevankeyboards/minivan/rules.mk

@@ -28,3 +28,4 @@ MIDI_ENABLE = no            # MIDI controls
 UNICODE_ENABLE = no         # Unicode
 BLUETOOTH_ENABLE = no       # Enable Bluetooth with the Adafruit EZ-Key HID
 AUDIO_ENABLE = no           # Audio output on port C6
+RGBLIGHT_ENABLE = yes		# Enable support for RGB LEDs