icarus: Remove ability to change fpga_count at runtime
icarus: Move work_division autodetection code into new icarus_probe_work_division function
icarus: Ensure fpga_count is finalised before add_cgpu is called
DevAPI: Allow using device_proc_by_id with const struct cgpu_info
icarus: Processor detail support
Merge branch 'icarus_proc' into bfgminer