arm64: dts: rockchip: convert PCIe to use per-lane PHYs for rk3339

Convert all RK3399 platforms to use per-lane PHY model in order to save
more power by idling unused lane(s).

Tested-by: Jeffy Chen <jeffy.chen@rock-chips.com>
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Brian Norris <briannorris@chromium.org>