handling of endianess in both rx and tx csv, binary data is alwais (for now) in LE format

I did test this patch and as far as I can see it works, however, I have noticed a couple of strange things that are probably not related to the path but should be investigated further
1) I need to reload the fpga to actually have samples, if I do a reading , quite and then restart bladerf cli I get no samples
2) I have a strangely constant reading, pretty much unlikely to happen and I do not know who is to blame...