fosphor_display: Filter received tags by EOB

[ejk43]

Hi all, this is based on a discussion I had recently on the IRC about fosphor debugging...

I have a local change to gr-ettus that outputs timetag/sample rate item tags on the output of each rx_streamer, which broke fosphor... It turns out fosphor is using item tags for framing, but was not filtering based on end-of-burst.

This quick fix will let us add other item tags to gnuradio streams going into the fosphor display without breaking fosphor.

[mbr0wn]

@trungnob Weren't you running fosphor on the E310?

[ejk43]

Quick comment: fosphor is working on rfnoc-devel AFAIK

...This is a future-looking fix in case there's ever any item tags attached to an rfnoc RX steam that are not eob indicators (in my case, I add a time tag at the start of each steam and after each eob to maintain timing information).

[mbr0wn]

Thanks for the fix. Should have merged this ages ago.