libbladeRF: [WIP] Start of LMS cleanup
libbladeRF: [WIP] < 1/3 through review of LMS code.

Minor aesthetic changes, jotted down a few notes, additional input
validation.
libbladeRF: [WIP] Removed peak detect enable

Per discussion with bpadalino, this was a vestige of some planned
functionality that wasn't completed -- removing for the time being.
libbladeRF: [WIP] Notes, readability, and debug print fix

Prepared a few items (marked XXX) for later discussions and review.
libbladeRF: [WIP] Removed BLADERF_LB_RF_LNA_START

If this is only a placeholder that should never be used, it shouldn't
be presented in external library interface.
libbladeRF: [WIP] Trimmed items from lms_lpf_init, style cleanup