net: designware: Add reset ctrl to driver

Add code to reset all reset signals as in Ethernet DT node. A reset
property is an optional feature, so only print out a warning and do not
fail if a reset property is not present.

If a reset property is discovered, then use it to deassert, thus
bringing the IP out of reset.

Signed-off-by: Ley Foon Tan <ley.foon.tan@intel.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>