drivers: stepper: tmc2209: Allow counter dts property

Enables use of the counter dts property which allows to configure a counter
device as the timing source for the stepping.

Signed-off-by: Fabian Blatz <[email protected]>

Author: faxe1008

dts/bindings/stepper/adi/adi,tmc2209.yaml

@@ -24,6 +24,7 @@ include:
       - step-gpios
       - dir-gpios
       - en-gpios
+      - counter
 
 properties:
   msx-gpios: