dt-bindings: display: bridge: renesas,rzg2l-mipi-dsi: Document RZ/V2L support

Document RZ/V2L DSI bindings. RZ/V2L MIPI DSI is identical to one found on
the RZ/G2L SoC. No driver changes are required as generic compatible
string "renesas,rzg2l-mipi-dsi" will be used as a fallback.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20221122195413.1882486-1-biju.das.jz@bp.renesas.com