Merge net branch into master

Main changes:

- DHCPv4 retransmission counter fix
- Multicast address handling fixes

----------------------------------------------------------------
Jukka Rissanen (4):
      net: nbuf: Fix constness of data param in net_nbuf_append
      net: if: Change the addr param type in net_if_ipv6_maddr_add/rm
      net: context: Fix the multicast address lookup in bind
      net: if: Change the iface param in net_if_ipv6_maddr_lookup

Marcus Shawcroft (1):
      net/dhcpv4: Ensure the retransmission attempts counter gets reset.

 include/net/nbuf.h          |  2 +-
 include/net/net_if.h        | 10 ++++++----
 subsys/net/ip/dhcpv4.c      |  2 ++
 subsys/net/ip/nbuf.c        |  5 +++--
 subsys/net/ip/net_context.c |  2 +-
 subsys/net/ip/net_if.c      |  8 ++++++--
 6 files changed, 19 insertions(+), 10 deletions(-)

Change-Id: I0c459de1b8555c0dad9b27c5d83ed4e84a11eacc
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>