drm/vc4: vec: Use TV Reset implementation

The analog TV properties created by the drm_mode_create_tv_properties() are
not properly initialised at reset. Let's switch our implementation to call
drm_atomic_helper_connector_tv_reset().

Reviewed-by: Noralf Trønnes <noralf@tronnes.org>
Tested-by: Mateusz Kwiatkowski <kfyatek+publicgit@gmail.com>
Acked-in-principle-or-something-like-that-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://lore.kernel.org/r/20220728-rpi-analog-tv-properties-v10-15-256dad125326@cerno.tech


Signed-off-by: Maxime Ripard <maxime@cerno.tech>