- open/close/read and poll need to take the core lock as well.
- when the tuner goes to sleep we should set std_set_in_tuner_core
to 0 since the tuner loses the firmware at that time.
- initialize the tuner if std_set_in_tuner_core == 0 whenever:
1) g/s_tuner, s_std or s_frequency is called
2) read or poll is called
3) streamon is called