phy: phy-rockchip-inno-usb2: add support for RK3308 USB phy

The RK3308 SoC uses a slightly different USB phy than other Rockchip
parts.
This commit adds support for that phy.

Signed-off-by: Tobias Schramm <t.schramm@manjaro.org>
Link: https://lore.kernel.org/r/20210514150044.2099298-3-t.schramm@manjaro.org


Signed-off-by: Vinod Koul <vkoul@kernel.org>