phy: renesas: rcar-gen3-usb2: Fix ID check logic with VBUS valid

phy: renesas: rcar-gen3-usb2: Fix ID check logic with VBUS valid

The existing ID detection logic returned false when both IDDIG and
VBUSVALID were set, which caused incorrect role determination in some
cases. The condition:

    !(device && !vbus_valid)

did not properly reflect the intended relationship between IDDIG and
VBUSVALID signals.

Update the logic to:

    return vbus_valid ? device : !device;

This ensures that when VBUS is valid, the role follows the IDDIG value,
and when VBUS is not valid, the role is inverted, matching the expected
OTG behavior.

Fixes: b725741f1c21 ("phy: renesas: rcar-gen3-usb2: Add support for RZ/T2H SoC")
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20250821155957.1088337-1-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>