rfnoc: Added reset for FFT core in FFT RFNoC block. This is a workaround to fix the random FFT offset caused by the FFT RFNoC block receiving incorrectly sized packets.
rfnoc: Updated fpga-src
rfnoc: Overhauled X300 crossbar debug / statistics script.

- Reads the number of ports attached to crossbar and sizes network stats table appropriately

- Modified code to work with new dedicated crossbar readback bus
--> Original readback bus did not have enough address space for readback stats of a 16x16 xbar

- Removed broken network device enumeration code

- Renamed variables / consts for consistency
rfnoc: Updated fpga-src
ks: wrong TX CPU format was being printed (was printing RX for TX)
math: Added a portable log2()
b200: Make the master clock rate auto-configurable

When no master_clock_rate is defined, the B200 driver will now
select a suitable clock rate automatically based on the selected
sampling rate.
The selected tick rate is a multiple of the LCM of tx and rx rates.

Auto-setting is done every time a streamer is generated or the sampling
rate is configured.
x300: Clarified FPGA compat error message
b200: serialized access to get_rx/tx_stream
Merge branch 'maint'

Conflicts:
	host/lib/usrp/b200/b200_impl.hpp
uhd: replaced the `images_error` with a generic utility error

- Deleted images.*, moved functionality to paths.*
- Applies for all devices that check FPGA or FW compat numbers
- Adds generic utility search tool
Merge branch 'master' into rfnoc-devel

Conflicts:
	host/lib/usrp/x300/x300_impl.cpp