Allow changing number of outstanding requests in memread tests

Change-Id: If8f128c8b10d2206dc322920bf6b3b2e1b69ab7f
added MemreadEngineBufferSize parameter to memread tests

Change-Id: Id866b8142095fac9816807da2620838118666cba
memread_manyclients/performance.txt

Change-Id: I7ffcce2b83b7976731e7bec65e71290549abac80
fix ifdef

Change-Id: I065a4af33722629c4abec29e728a68e0791a3ebb
a couple more performance (non) results)

Change-Id: I4c3e76255adaeda5adf006c8c02db0936bcadee5
added make target programflash.board

Change-Id: I15afde3d594d5ee5c2ee63dbb5ac6714deee43fe