phy: renesas: rcar-gen3-usb2: disable runtime pm in case of failure

phy: renesas: rcar-gen3-usb2: disable runtime pm in case of failure

pm_runtime_enable() will decrease power disable depth. Thus a pairing
increment is needed on the error handling path to keep it balanced.

Fixes: 5d8042e95fd4 ("phy: rcar-gen3-usb2: Add support for r8a77470")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wang Li <wangli74@huawei.com>
Link: https://lore.kernel.org/r/20201126024412.4046845-1-wangli74@huawei.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>