arm64: dts: verdin-imx8mp: disable usb port power control

Disable port power control on Verdin USB_1/2 as we use regular
fixed-regulators with Verdin USB_1/2_EN as enable GPIOs.

Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>