dt-bindings: display: Add D1 display engine compatibles

Allwinner D1 contains a display engine 2.0. It features two mixers, a
TCON TOP (with DSI and HDMI), one TCON LCD, and one TCON TV.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Samuel Holland <samuel@sholland.org>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20220424162633.12369-3-samuel@sholland.org