bitfury: Simplify dynamic osc6_bits logic such that the range is defined in one place
bitfury: Remove useless debugging
Bugfix: bitfury: Fix tv_stat to persist
bitfury: More debugging info for dynamic osc6_bits
bitfury: Only use dynamic osc6_bits with boards that support it explicitly (BFSB and Metabank for now)
bitfury_do_io: Make use of timer_elapsed