MFC r315404:
Add basic support for VIMAGE to the LinuxKPI and ibcore.

Support is implemented by mapping Linux's "struct net" into FreeBSD's
"struct vnet". Currently only vnet0 is supported by ibcore.

Sponsored by: Mellanox Technologies

MFC r315405, r323351 and r323364:
Add helper function similar to ip_dev_find() to the LinuxKPI to lookup
a network device by its IPv6 address in the given VNET.

Sponsored by: Mellanox Technologies

MFC r270710 and r270821:
- Update the OFED Linux Emulation layer as a preparation for a
hardware driver update from Mellanox Technologies.
- Remove empty files from the OFED Linux Emulation layer.
- Fix compile warnings related to printf() and the "%lld" and "%llx"
format specifiers.
- Add some missing 2-clause BSD copyrights.
- Add "Mellanox Technologies, Ltd." to list of copyright holders.
- Add some new compatibility files.
- Fix order of uninit in the mlx4ib module to avoid crash at unload
using the new module_exit_order() function.

Sponsored by: Mellanox Technologies

MFC r270710 and r270821:
- Update the OFED Linux Emulation layer as a preparation for a
hardware driver update from Mellanox Technologies.
- Remove empty files from the OFED Linux Emulation layer.
- Fix compile warnings related to printf() and the "%lld" and "%llx"
format specifiers.
- Add some missing 2-clause BSD copyrights.
- Add "Mellanox Technologies, Ltd." to list of copyright holders.
- Add some new compatibility files.
- Fix order of uninit in the mlx4ib module to avoid crash at unload
using the new module_exit_order() function.

Sponsored by: Mellanox Technologies