arm64: dts: rockchip: enable typec-phy for rk3399-sapphire

Commit c301b327 ("arm64: dts: rockchip: add usb3-phy otg-port
support for rk3399") caused a regression regarding the USB3 type-A port.
During boot, the following message appears a few times:

  dwc3: failed to initialize core

The driver is deferred waiting for the typec-phy, but this never happens
bceause is disabled. So, enable it.

The offending commit was reverted in 4.16-rc but can be re-applied
after enabling the typec phys.

Reported-by: Vicente Bergas <vicencb@gmail.com>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Tested-by: Vicente Bergas <vicencb@gmail.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>