This interface allows to use a Calypso based phone (e.g. Motorola
C1XX) as a SIM card reader. It basically implements a few L1CTL
messages that are used to interact with the SIM card through
the OsmocomBB 'layer1' firmware.
Please note, that this is an experimental implementation, and
there is a risk that SIM programming would fail. Nevertheless,
I've managed to program and read one of my SIMs a few times.
Change-Id: Iec8101140581bf9e2cf7cf3a0b54bdf1875fc51b