rdma/ucm: support querying when IB paths are not reversible

rdma/ucm: support querying when IB paths are not reversible

The current query_route call can return up to two path records.
The assumption being that one is the primary path, with optional
support for an alternate path.  In both cases, the paths are
assumed to be reversible and are used to send CM MADs.

With the ability to manually set IB path data, the rdma cm
can eventually be capable of using up to 6 paths per
connection:

	forward primary, reverse primary,
	forward alternate, reverse alternate,
	reversible primary path for CM MADs
	reversible alternate path for CM MADs.

(It is unclear at this time if IB routing will complicate this.)
In order to handle more flexible routing topologies, add a new
command to report any number of paths.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>