dt-bindings: reset: renesas,rzv2h-usb2phy: Document RZ/V2N SoC support

dt-bindings: reset: renesas,rzv2h-usb2phy: Document RZ/V2N SoC support

Document support for the USB2PHY reset controller found on the Renesas
RZ/V2N (R9A09G056) SoC. The reset controller IP is functionally identical
to that on the RZ/V2H(P) SoC, so no driver changes are needed. The existing
`renesas,r9a09g057-usb2phy-reset` compatible will be used as a fallback
for the RZ/V2N SoC.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20250528133031.167647-1-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>