- add tests for pipe_close (while TDs are active)
- add tests for device unplugged
add tesst & implement the async_advance_isr to clean up "REMOVING" queue head
- add helper find previous qhd
- add remove qhd from async list
- add is_removing field for async advance isr to clean up
add pipe close for control pipe & bulk pipe (with tests)
add helper get qhd from pipe_handle
- interrupt source identifying
- for async list process
refractor control_xfer to use insert_qtd_to_qhd
- add test for control xfer interrupt processing
- add code for faking ehci controller async list scheduling & processing
- add prototype for void usbh_isr(pipe_handle_t pipe_hdl, uint8_t class_code);