major refactor to generalize cdch serial driver

- add common 2 stage set line coding for driver without direct set_line_coding support e.g ftdi, cp210x, ch34x
- add common cdch_process_line_state_on_enum() to handle cfg line state on enum e.g CFG_TUH_CDC_LINE_CONTROL/CODING_ON_ENUM
- refactor cdch_internal_control_complete and user_complete_cb to be managed by tuh_cdc_ API instead of serial driver

Author: hathach