This patch add get_linestate and set_linestate phy ops for rockchip platforms to get the usb dp/dm status and set the dp/dm voltage by software. For the time being, only support rk3308. Signed-off-by: William Wu <william.wu@rock-chips.com> Change-Id: I4388acb688cfafe917d4118c694bf6f2d23fd7f6