IB: Set IOVA/LENGTH on IB_MR in core/uverbs layers

IB: Set IOVA/LENGTH on IB_MR in core/uverbs layers

Set 'iova' and 'length' on ib_mr in ib_uverbs and ib_core layers to let all
drivers have the members filled. Also, this commit removes redundancy in
the respective drivers.

Previously, commit 962ad154d57b1 ("IB/uverbs: Set IOVA on IB MR in uverbs
layer") changed to set 'iova', but seems to have missed 'length' and the
ib_core layer at that time.

Fixes: 962ad154d57b1 ("IB/uverbs: Set IOVA on IB MR in uverbs layer")
Signed-off-by: Daisuke Matsuda <matsuda-daisuke@fujitsu.com>
Link: https://lore.kernel.org/r/20220921080844.1616883-1-matsuda-daisuke@fujitsu.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>