arm64: dts: verdin-imx8mp: remove usb_2 over-current detection disabling

The disable-over-current property is only applicable for the
ci-hdrc-usb2 and dwc2 drivers while the i.MX 8M Plus integrates dwc3
IP. Therefore remove this property which does not really serve any
purpose here.

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