dt-bindings: pinctrl: renesas: Document RZ/V2L pinctrl

Document Renesas RZ/V2L pinctrl bindings.  The RZ/V2L SoC is package-
and pin-compatible with RZ/G2L.  No driver changes are required as the
RZ/G2L compatible string "renesas,r9a07g044-pinctrl" will be used as a
fallback.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220110134659.30424-7-prabhakar.mahadev-lad.rj@bp.renesas.com


Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>