IB/uverbs: Set IOVA on IB MR in uverbs layer

Set IOVA on IB MR in uverbs layer to let all drivers have it, this
includes both reg/rereg MR flows.
As part of this change cleaned-up this setting from the drivers that
already did it by themselves in their user flows.

Fixes: e6f03301

 ("mlx4_ib: set user mr attributes in struct ib_mr")
Link: https://lore.kernel.org/r/20200630093916.332097-3-leon@kernel.org
Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>