LU-12400 lnet: Infiniband sg_dma changes for linux 5.1

LU-12400 lnet: Infiniband sg_dma changes for linux 5.1

IB/core: Remove ib_sg_dma_address() and ib_sg_dma_len()
Linux-commit: a163afc88556e099271a7b423295bc5176fcecce

This simplification can be applied to mainline 3.15 and later
however the test should remain for 3rd party ib driver support

Test-Parameters: trivial
Cray-bug-id: LUS-7600
Signed-off-by: Shaun Tancheff <stancheff@cray.com>
Change-Id: I4824b3b737388a3fc0aec43b2d8e5d10f871ccdd
Reviewed-on: https://review.whamcloud.com/35497
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Petros Koutoupis <pkoutoupis@cray.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>