MFC r277396, r278681, r278865, r278924, r279205, r280208,
r280210, r280764 and r280768:

Update the Linux compatibility layer:
- Add more functions.
- Add some missing includes which are needed when the header files
are not included in a particular order.
- The kasprintf() function cannot be inlined due to using a variable
number of arguments. Move it to a C-file.
- Fix problems about 32-bit ticks wraparound and unsigned long
conversion. Jiffies or ticks in FreeBSD have integer type and are
not long.
- Add missing "order_base_2()" macro.
- Fix BUILD_BUG_ON() macro.
- Declare a missing symbol which is needed when compiling without -O2
- Clean up header file inclusions in the linux/completion.h, linux/in.h
and linux/fs.h header files.

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 r277396, r278681, r278865, r278924, r279205, r280208,
r280210, r280764 and r280768:

Update the Linux compatibility layer:
- Add more functions.
- Add some missing includes which are needed when the header files
are not included in a particular order.
- The kasprintf() function cannot be inlined due to using a variable
number of arguments. Move it to a C-file.
- Fix problems about 32-bit ticks wraparound and unsigned long
conversion. Jiffies or ticks in FreeBSD have integer type and are
not long.
- Add missing "order_base_2()" macro.
- Fix BUILD_BUG_ON() macro.
- Declare a missing symbol which is needed when compiling without -O2
- Clean up header file inclusions in the linux/completion.h, linux/in.h
and linux/fs.h header files.

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