Log message:
yosys: only uses Xdot

use DEPENDS on graphviz instead of its bl3.mk

Bump PKGREVISION.

Log message:
*: recursive bump for graphviz 10.0.1

Log message:
yosys: fix interpreter in yosys-config script

Bump PKGREVISION.

Log message:
KERN_PROC_PATHNAME is slightly different on NetBSD vs FreeBSD; handle this
difference correctly.  Bump package revision to 1.

Log message:
Add a package for yosys:

The Yosys Open SYnthesis Suite is a framework for RTL synthesis tools. It
currently has extensive Verilog-2005 support and provides a basic set of
synthesis algorithms for various application domains.

Together with nextpnr-ice40 and icestorm, this forms a toolchain that can
be used to synthesize and program designs for Lattice iCE40-family FPGAs.