Add support for LEIA target

[GotoHack]

This add support for the LEIA by H2LAB target: an open hardware and open source device targeting smart card side-channel analysis (SCA) and evaluation, for educational and evaluation purpose. It implements a fully controlled ISO7816 stack with a dedicated custom hardware platform to acquire clean measurements for SCA characterization.

[colinoflynn]

Finally reviewing (oops) - we try to avoid forcing dependencies as it can break a lot of stuff. Won't accept as-is but leaving open as will rework to avoid setup.py changes.