ib/port_attr: report active width as part of port attributes

ib/port_attr: report active width as part of port attributes

Return the active width in the port attributes reported by the HCA.
Because the kernel and user space share the same source
files, to avoid breaking the ABI, rename link_width_supported
field to active_width and use that field to return the value.
link_width_supported is currently uninitialized and in the
svn tree unused, so repurposing the field should have minimal
impact.  However, this change will break the API.
Applications that reference the link_width_supported field
from struct _ib_port_attr will require a minor update if recompiled.

Update winverbs to report this value and fill in other
missing fields from the port attribute structure.  This fix
allows reporting the correct values through the libibverbs
port and ibv_devinfo example utility.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>
git-svn-id: svn://openib.tc.cornell.edu/gen1@2366 ad392aa1-c5ef-ae45-8dd8-e69d62a5ef86