samples: sensor: qdec: fix mimxrt1050_evk build failure.

Recent PR turned on test case for twister which revieled a bug
with building the test case for RT1050 EVK. The touch_controller
DTS node was removed a by commit 57ad325e and further deprecated
by bde07beb5 when the platform was converted to tread displays as
shields.

Signed-off-by: David Leach <david.leach@nxp.com>