phy: uniphier-usb3hs: Change Rx sync mode to avoid communication failure

In case of using default parameters, communication failure might occur
in rare cases. This sets Rx sync mode parameter to avoid the issue.

Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>