RDMA/uverbs: Add an ioctl method to destroy an object

Add an ioctl method to destroy the PD, MR, MW, AH, flow, RWQ indirection
table and XRCD objects by handle which doesn't require any output response
during destruction.

Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>