ARM: dts: imx6dl: vicut1: Address USB related warnings

This patch addresses several USB-related warnings in the device tree for
the imx6dl vicut1 system. Specifically, it disables the unused
usbphynop1 and usbphynop2 USB PHYs, and disables unsupported
over-current detection. This action mitigates the following kernel
warnings:
usb_phy_generic usbphynop1: dummy supplies not allowed for exclusive requests
usb_phy_generic usbphynop2: dummy supplies not allowed for exclusive requests
imx_usb 2184200.usb: No over-current polarity defined

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>