The network L2 recv handler needs to set the initial value for
IP protocol type (IPv4 or IPv6). Otherwise the recv data check
in net_core.c:process_data() will not work properly if IPv4
is enabled.
Change-Id: I5684cd10e5d79e13a977406729ea68313e689c9b
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>