rockchip: rk3399-puma: Remove obsolete DTS node 'vcc5v0_host'.

vcc5v0_host and usbhub_enable share gpio4 RK_PA3,
which is a problem during probing (the second probe
will trigger a -EBUSY, when trying to get the gpio handle).

An analysis of the situation shows, that both regulators
are actually describing the same supply.

This patch removes the (currenlty not successful probing)
regulator vcc5v0_host from the DTS and adds the pinctrl-*
setting to usbhub_enable.

Signed-off-by: Christoph Muellner <christoph.muellner@theobroma-systems.com>
Reviewed-by: Phiilipp Tomsich <philipp.tomsich@theobroma-systems.com>