Merge branch 'uverbs_dev_cleanups' into rdma.git for-next

Merge branch 'uverbs_dev_cleanups' into rdma.git for-next

For dependencies, branch based on rdma.git 'for-rc' of
https://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma.git/

Pull 'uverbs_dev_cleanups' from Leon Romanovsky:

====================
Reuse the char device code interfaces to simplify ib_uverbs_device
creation and destruction. As part of this series, we are sending fix to
cleanup path, which was discovered during internal review,

The fix definitely can go to -rc, but it means that this series will be
dependent on rdma-rc.
====================

* branch 'uverbs_dev_cleanups':
  RDMA/uverbs: Use device.groups to initialize device attributes
  RDMA/uverbs: Use cdev_device_add() instead of cdev_add()
  RDMA/core: Depend on device_add() to add device attributes
  RDMA/uverbs: Fix error cleanup path of ib_uverbs_add_one()

Resolved conflict in ib_device_unregister_sysfs()

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>