reset: Add USB2PHY port reset driver for Renesas RZ/V2H(P)

reset: Add USB2PHY port reset driver for Renesas RZ/V2H(P)

Implement a USB2PHY port reset driver for the Renesas RZ/V2H(P) SoC.
Enable control of USB2.0 PHY reset and power-down operations, including
assert and deassert functionalities for the PHY.

Leverage device tree (OF) data to support future SoCs with similar USB2PHY
hardware but varying register configurations. Define initialization values
and control register settings to ensure flexibility for upcoming platforms.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Fabrizio Castro <fabrizio.castro.jz@renesas.com>
Link: https://lore.kernel.org/r/20250415195131.281060-3-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>