net: lwip: provide net_start_again()

Implement net_start_again() when NET_LWIP=y in a very similar way to
NET. This will be used in a future commit to determine if a failed
ping needs to be tried again on a different interface.

Signed-off-by: Jerome Forissier <jerome.forissier@linaro.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
3 files changed