IB/core: Add XRQ capabilities

This patch adds following TM XRQ capabilities:

* max_rndv_hdr_size - Max size of rendezvous request message
* max_num_tags - Max number of entries in tag matching list
* max_ops - Max number of outstanding list operations
* max_sge - Max number of SGE in tag matching entry
* flags - the following flags are currently defined:
    - IB_TM_CAP_RC - Support tag matching on RC transport

Signed-off-by: Artemy Kovalyov <artemyko@mellanox.com>
Reviewed-by: Yossi Itigin <yosefe@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>