tests: drivers: build_all: stepper: Adjust tmc2209 device instance

Adds the counter property to the tmc2209 node to ensure counter dependant
step-dir code is build by CI.

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

Author: faxe1008

tests/drivers/build_all/stepper/gpio.dtsi

@@ -22,6 +22,7 @@ test_tmc2209: tmc2209_motor {
 	en-gpios = <&test_gpio 0 0>;
 	step-gpios = <&test_gpio 0 0>;
 	dir-gpios = <&test_gpio 0 0>;
+	counter = <&counter0>;
 };
 
 drv8424: drv8424 {