dt-bindings: phy-rockchip-typec: move extcon property to be optional.

The extcon property is used to detect the cable-state but some boards
just connect the type-c phy to a regular USB-A connector without any
power-delivery and thus no controller reporting the cable-state.
So the extcon property is not really a required property, move it to be
optional instead.

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

dt-bindings: phy-rockchip-typec: deprecate some register properties.

As now the following register properties are in the driver, document as
deprecated these properties and recommend to not use them on new bindings.

The deprecated properties are:

- rockchip,typec-conn-dir : the register of type-c connector direction
- rockchip,usb3tousb2-en : the register of type-c force usb3 to usb2
enable control.
- rockchip,external-psm : the register of type-c phy external psm clock
selection.
- rockchip,pipe-status : the register of type-c phy pipe status.

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

Documentation: bindings: add dt doc for Rockchip USB Type-C PHY

This patch adds a binding that describes the Rockchip USB Type-C PHY
for rk3399

Signed-off-by: Chris Zhong <zyw@rock-chips.com>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>