the old dwc_otg driver is starting to fall apart and fails on newer 3g
modems and some storage devices. switch to the upstream dwc2 driver which
is no longer in staging/.
Signed-off-by: John Crispin <blogic@openwrt.org>
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@42446 3c298f89-4303-0410-b956-a3cf2f4a3e73