IB/hfi1, qib, rdmavt: Move two IB event functions into rdmavt

Add rvt_rc_error() and rvt_comm_est() as shared functions in
rdmavt, moved from hfi1/qib logic.

Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Brian Welty <brian.welty@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>