Char: serial167, remove bottomhalf

- Cy_EVENT_OPEN_WAKEUP is simple wake_up
- Cy_EVENT_HANGUP is wake_up + tty_hangup, which schedules its own work
- Cy_EVENT_WRITE_WAKEUP is tty_wakeup which may be called directly too

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>