IB/rdmavt: Add srq functionality to rdmavt

Fill in srq function stubs with code derived from hfi1 and qib.
Move necessary functions and data structure members as well.

Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Reviewed-by: Harish Chegondi <harish.chegondi@intel.com>
Signed-off-by: Jubin John <jubin.john@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>