Transceiver52M: Add B210 support

Identical to B200 support, but explicitly check for the device type
name.

Signed-off-by: Thomas Tsou <tom@tsou.cc>
Transceiver52M: Remove support for ancient libusrp versions

Current functionality with these old versions is questionable.
There is no reason to use any version of GNU Radio / libusrp older
than 3.3. Version 3.4.2 is the only recommended version for USRP1
users.

Non-USRP1 users must use UHD driver from Ettus Research.

Signed-off-by: Thomas Tsou <tom@tsou.cc>
Transceiver52M: Add SSE conversion for non-multiples of 4

Extend handling of SSE floating point and integer conversions
to non-multiples of 4. This allows us to handle a few odd
cases. Notably (625 * 2) integer to float conversions on the
receive path at 1 sample-per-symbol.

Signed-off-by: Thomas Tsou <tom@tsou.cc>
Transceiver52M: Add 64 MHz resampling option with B100

Move B100 to the resampling interface with default
clocking. This temporarily resolves undetermined
FPGA clocking issues. This also provides extensible
support for multiple clocking rates and resampling
ratios.

Signed-off-by: Thomas Tsou <tom@tsou.cc>
Transceiver52M: Reduce and place bounds checking on I/O buffers

Previous send and receive buffers at the radio interface were
arbitrarily set to a sufficient size. For normal (non-resampling)
devices, use a block (chunk) size of 625 samples. For 64 or 100
MHz resampling devices, use 4 times the reduced resampling
numerator or denominator and provide bounds checking where
appropriate.

Signed-off-by: Thomas Tsou <tom@tsou.cc>
Transceiver52M: Deallocate high level resources on shutdown

This primarily addresses the error case at initialization.
In the event that the transceiver fails to start, we should
be able cleanly shutdown and release while providing a useful
reason for exiting.

After the radio is started and threads launched, there
are no thread state variables or shutdown messaging between
threads, and the transceiver cannot be consistently
shutdown. This issue remains to be solved.

Signed-off-by: Thomas Tsou <tom@tsou.cc>