dt-bindings: reset: renesas,rzv2h-usb2phy: Document RZ/G3E USB2PHY reset

dt-bindings: reset: renesas,rzv2h-usb2phy: Document RZ/G3E USB2PHY reset

Document USB2PHY reset controller bindings for RZ/G3E ("R9A09G047") SoC.

The RZ/G3E USB2PHY reset controller is functionally identical to the one
found on the RZ/V2H(P), so no driver changes are needed. The existing
"renesas,r9a09g057-usb2phy-reset" will be used as a fallback compatible
for this IP.

Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>