drm/exynos: fimd: move handle vblank position in TE handler

For providing VBLANK information, drm_handle_vblank() should
be called properly, but it is blocked by wait_vsync_event
condition which is set by manager_ops->wait_for_vblank().
So moves it out from wait_vsync_event routine.

Signed-off-by: YoungJun Cho <yj44.cho@samsung.com>
Acked-by: Inki Dae <inki.dae@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Inki Dae <inki.dae@samsung.com>