Make version comparison readable

This also fixes an endian issue with the comparison of the last two
bytes.  According to the logging output, these bytes are in little
endian order so the last byte is more significant in the comparison.
Rename `'s/supported_device/known_device/g'`

An `ambit_supported_device_t` with a `supported` value of `false` is
confusing at best.
Export clock's support status in `ambit_device_info_t`

This allows for dropping the `ambit_known_device_t` pointer from
`ambit_object_t`.
Fix log message