Several refactors and cleanups (#1102)

- Extract BM##_set_job_difficulty_mask into a single function
- Set self_test difficulty before ASIC_init to eliminate ASIC_set_job_difficulty_mask
- Fixed some capitalisations of GLOBAL_STATE and some others
- Thermal.c: pass DEVICE_CONFIG by pointer instead of by value

components/asic/include/common.h

@@ -16,5 +16,6 @@ int _largest_power_of_two(int num);
 
 int count_asic_chips(uint16_t asic_count, uint16_t chip_id, int chip_id_response_length);
 esp_err_t receive_work(uint8_t * buffer, int buffer_size);
+void get_difficulty_mask(uint16_t difficulty, uint8_t *job_difficulty_mask);
 
 #endif /* COMMON_H_ */