IB/hfi1: Integrate OPFN into RC transactions

OPFN parameter negotiation allows a pair of connected RC QPs to exchange
a set of parameters in succession. This negotiation does not commence
till the first ULP request. Because OPFN operations are operations
private to the driver, they do not generate user completions or put the
QP into error when they run out of retries. This patch integrates the
OPFN protocol into the transactions of an RC QP.

Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Mitko Haralanov <mitko.haralanov@intel.com>
Signed-off-by: Kaike Wan <kaike.wan@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>