SM6FBQ / HackRF clone - History

PortaPack: Add check for PortaPack clock reference, use if present.

Wow, it takes a lot of ugly code to keep blinky happy...

Si5351C: Extract best block source function into hackrf_core.

It's not an Si5351C driver thing, but a HackRF thing. Also added a driver function to check if CLKIN signal is valid, and made use of it, instead of opaque register read code.

PortaPack: Lots of clean-up

Perform PortaPack initialization separately from and earlier than UI initialization. Track if PortaPack was detected, provide (mostly useless) pointer if so. Put "weak" declarations into respective headers. Moving #includes around.

PortaPack: Refactor general UI functions into separate PortaPack API.

PortaPack: Hide UI types that don't need to be exposed.

PortaPack: Extract non-UI code into separate portapack.[ch] module.

I'll be adding some non-UI API functions to the top-level PortaPack structure.

CPLD: Change tool interface to accept --xsvf and --hackrf-data args.

More args coming shortly...