Add support for KerberosSDR

[andyn]

Now that KerberosSDR is available, it'd be neat to have the waterfall visualization working on the hardware. I'll probably look into it as I've got the kit now and I'm already familiar with the DF Python code.

[Kun-Narra]

I just got KerberosSDR to try. thanks for your contribution.

[Kun-Narra]

I had few issues with libraries but finally it work on my KerberosSDR.
I will fiddle around.