Patch fixes following build error when
CONFIG_NET_IPv6 && !CONFIG_NET_ICMPv6 && CONFIG_NET_ETHERNET:
nuttx/staging/libnet.a(neighbor_ethernet_out.o): In function `neighbor_ethernet_out':
nuttx/net/neighbor/neighbor_ethernet_out.c:188: undefined reference to `icmpv6_solicit'
IPv6 without ICMPv6 is not very useful, but at least this patch
allows neighbor_ethernet_out() to be used with a packet socket or
with multicast address (point-to-point IPv6 links) even in that case.
Signed-off-by: Juha Niskanen <juha.niskanen@haltian.com>
ebb5fb7480