Tsl2561 and SI7021 Device Demos no longer working

[AreYouLoco]

PulseView demo for follow along logic analyzer mode

I managed to make it work on Linux. Two days fighting and the issue was that I was missin libserialport developer headers so libsigrok was compiled without support for libserialport. Here is fix for compiling on Linux and it works when you add udev rule or run as root.

It was initially done by @phdussud and I just fixed compiling on Linux. So its already done.