dt-bindings: usb: renesas,usb3-peri: Document RZ/V2MA bindings

Document RZ/V2MA usb3-peri bindings. RZ/V2MA usb3-peri is identical
to one found on the RZ/V2M SoC. No driver changes are required as
generic compatible string "renesas,rzv2m-usb3-peri" will be used as
a fallback.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230121145853.4792-4-biju.das.jz@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>