Early exits (goto, break, return) from for_each_child_of_node() required
an explicit call to of_node_put(), which was not introduced with the
break if cnt == MAX_CRTC.
Add the missing of_node_put() before the break.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: d761b9450e31 ("drm/mediatek: Add cnt checking for coverity issue")
Signed-off-by: Javier Carrasco <javier.carrasco.cruz@xxxxxxxxx>