display: Add initial support for LCD screens attached to an MCU

Add support for displaying basic status information on ST7920 and
HD44780 based LCDs that are attached directly to a micro-controller.

Signed-off-by: Marcio Teixeira <marcio@alephobjects.com>
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

klippy/gcode.py

@@ -78,6 +78,9 @@ class GCodeParser:
         self.position_with_transform = transform.get_position
     def stats(self, eventtime):
         return False, "gcodein=%d" % (self.bytes_read,)
+    def get_status(self, eventtime):
+        busy = self.is_processing_data
+        return {'speed_factor': self.speed_factor * 60., 'busy': busy}
     def printer_state(self, state):
         if state == 'shutdown':
             if not self.is_printer_ready: