phy: renesas: rcar-gen3-usb2: Allow SoC-specific OBINT bits via phy_data

Update the PHY driver to support SoC-specific OBINT enable bits by
introducing the `obint_enable_bits` field in the `rcar_gen3_phy_drv_data`
structure. This allows each SoC to specify bits required.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20250808215209.3692744-4-prabhakar.mahadev-lad.rj@bp.renesas.com


Signed-off-by: Vinod Koul <vkoul@kernel.org>