dt-bindings: phy: mediatek,dsi-phy: Add compatible for MT6795 Helio X10

Add a compatible string for MediaTek Helio X10 MT6795: this SoC uses
the same DSI PHY as MT8173.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Reviewed-by: Alexandre Mergnat <amergnat@baylibre.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230412112739.160376-3-angelogioacchino.delregno@collabora.com


Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>