Filter Wizard: fix misspelled variable names

Signed-off-by: Tim Harder <timothy.harder@analog.com>
Filter Wizard: explicitly write Rx/Tx RF bandwidth

Writing the BWTX/BWRX values via the loaded FIR filter doesn't seem to
change anything.

Signed-off-by: Tim Harder <timothy.harder@analog.com>
Filter Wizard: write data rates to target

Signed-off-by: Tim Harder <timothy.harder@analog.com>