ARM: dts: rockchip: add rk3036 usb2phy nodes and enable them on kylin

The rk3036 does contain a usb2phy, just until now it was just used
implicitly without additional configuration. As we now have the bits
in place for it getting actually controlled, add the necessary phy-node
to the GRF simple-mfd.

Enable the phy-ports in the same patch to not create bisectability
issues, as hooking up the phys to the usb controllers would create
probe deferrals until a board enables them. Doing everything in one
patch, solves that issue.

Only rk3036-kylin actually enabled the usb controllers, so is the only
board affected.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20250503201512.991277-4-heiko@sntech.de