arm64: dts: imx8mm-venice-gw71xx: fix USB OTG VBUS

The GW71xx does not have a gpio controlled vbus regulator but it does
require some pinctrl. Remove the regulator and move the valid pinctrl
into the usbotg1 node.

Fixes: bd306fdb ("arm64: dts: imx8mm-venice-gw71xx: fix USB OTG VBUS")
Signed-off-by: Tim Harvey <tharvey@gateworks.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>