The calls to drm_crtc_vblank_on/off should be paired into pipe_enable
and pipe_disable callbacks.
This patch adds the call to drm_crtc_vblank_off in pipe_disable callback.
Signed-off-by: Robert Chiras <robert.chiras@nxp.com> Reviewed-by: Laurentiu Palcu <laurentiu.palcu@nxp.com>