New port: devel/icestorm

Project IceStorm aims at documenting the bitstream format of Lattice
iCE40 FPGAs and providing simple tools for analyzing and creating
bitstream files.

WWW: http://www.clifford.at/icestorm

PR: 226711
Submitted by: Johnny Sorocil <jsorocil@gmail.com>
Differential Revision: https://reviews.freebsd.org/D15632