Change MMC from LPC1764 to 1768

All LPC176x are pin2pin compatible.
Change to version with more flash and RAM to make firmware update easier.

See https://github.com/lnls-dig/afc-hw/project/ohr-support/issues/239

assigned to @tprzywoz

changed milestone to %AFC v4.0

marked #89 (closed) as a duplicate of this issue

This issue seems to be solved by commit 1b2eb3ff.

Done

Solved in c961a747

closed