common: restructure EVD processing to handle EP destruction phase

common: restructure EVD processing to handle EP destruction phase

EVD processing in the common code will return unformated events
if EP context is invalid as a result of destruction. During
EP destruction, add changes to flush EVD and process DTO completions
before the EP freeing is called. Simplified the locking in the
EVD code to eliminate the unecessary and very confusing condition
checking of evd_producer_locking_needed.

new dapls_ep_flush_cqs() call created to syncronize flush and
event processing.

unnecessary KDAPL code removed in the EVD processing.

Signed-off-by: Arlin Davis <arlin.r.davis@intel.com>
Signed-off-by: Sean Hefty <sean.hefty@intel.com>