fixed read_beats to ask for ChannelType_Read, should make no difference in testmemrw and testmemcpy

Change-Id: I3ae3995e4fe75795f6b6f0a05d4c42270d24baae
added instance of mkConnection#(PS7, PortalTop)

Change-Id: I488efc470dffdfcd0828e5e456cb42071b9a0d2e