LU-10526 build: Ubuntu Kernel 4.4.0 lacks symbols used by o2iblnd.c

LU-10526 build: Ubuntu Kernel 4.4.0 lacks symbols used by o2iblnd.c

Recently, a change has been merged to "lnet/klnds/o2iblnd/o2iblnd.c" which
introduces the usage of IB_DEVICE_SG_GAPS_REG and IB_MR_TYPE_SG_GAPS.

Unfortunately, these symbols are not available in the 4.4.0 Kernels as used
by Ubuntu 14/16.

Additionally, there seems to be general warning against their use:
 - https://patchwork.kernel.org/patch/9573483/
 - https://lkml.org/lkml/2017/3/13/206

 Also, there is a related performance issue as reported in LU-10394.

The solution is to create a preprocessor guard around their use, so that
Kernels lacking these symbols will not use them and revert to using the older
IB_MR_TYPE_MEM_REG, instead.

Test-Parameters: trivial
Signed-off-by: Martin Schroeder <martin.h.schroeder@intel.com>
Change-Id: Ie835d6e04f3859634ba508c24dff1f27f1b24cf6
Reviewed-on: https://review.whamcloud.com/30893
Tested-by: Jenkins
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: Amir Shehata <amir.shehata@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>