drm/ast: Don't set struct drm_crtc_state.no_vblank explicitly

As ast does not initialize vblanking, atomic helpers initialize the
value of struct drm_crtc_state.no_vblank to be true. No need to set
it from within the driver.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200129120531.6891-4-tzimmermann@suse.de

drivers/gpu/drm/ast/ast_mode.c

@@ -833,8 +833,6 @@ static void ast_crtc_helper_atomic_flush(struct drm_crtc *crtc,
 	struct ast_vbios_mode_info *vbios_mode_info;
 	struct drm_display_mode *adjusted_mode;
 
-	crtc->state->no_vblank = true;
-
 	ast_state = to_ast_crtc_state(crtc->state);
 
 	format = ast_state->format;