Read memory doesn't work

[wt]

The do_command function in lpc55_isp/src/cmd.rs is not generic enough to handle the read memory request. The response includes data and a command packet. The current implementation of do_command will send the command correclty. However, when it gets the response, it goes into the DataPhase::Recv block and will attempt to fetch the data. However, when it sees the command framing packet that is part of the response, the program will bomb because it doesn't know how to handle that packet. I think that it may be necessary to refactor the code a bit to break do_command up to make it feasible to use that for handling the read memory command.

I'll see if I can find time for this, but this is just a hobby for me. :)