IB/rdmavt: Fix ab/ba include issues

The currently include file ordering for rdmavt headers has an
ab/ba include issue the precludes using inlines from rdma_vt.h
in rdmavt_qp.h.

At the heart of the issue is that rdma_vt.h includes rdmavt_qp.h.

Fix the ordering issue by adjusting rdma_vt.h to not require rdmavt_qp.h
and move qp related inlines to rdmavt_qp.h.

Additionally, promote rvt_mmap_info to rdma_vt.h since it is shared
by rdmavt_cq.h and rdmavt_qp.h.

Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>