phy: renesas: rcar-gen3-usb2: Use devm_pm_runtime_enable()

phy: renesas: rcar-gen3-usb2: Use devm_pm_runtime_enable()

Replace pm_runtime_enable() with devm_pm_runtime_enable() to ensure proper
cleanup if the probe fails. This change enhances driver reliability by
avoiding resource leaks, as the devm-managed version automatically handles
disabling at probe failure or device removal.

Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
Link: https://patch.msgid.link/ca028d41f84227efeccb0cbdff22fbf16e5cf6ab.1766405010.git.tommaso.merciai.xr@bp.renesas.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>