[chirp_devel] Fixed Frequency Radio

[Dan Smith]

> Would someone possibly give me a rough example. I added the following
> under the "def get_memory(self, number):" section thinking that would
> do the trick, put it appears to do nothing.
> 
>          mem.immutable = ["freq"]

Yeah, that should do it. If not, the UI might need a tweak to honor it 
or something.

In a pinch, just raise an exception in your driver if the frequency is 
different than you expect during a set_memory() operation. Alternately, 
you could just ignore what mem.freq is set to entirely.

--Dan