Various fixes for wl(4):
- Don't recurse driver mutex.
- Don't hold driver mutex across fubyte/subyte.
- Replace fubyte/subyte loops with copyin/copyout calls.
- Use relatively sane locking in wl_ioctl().
- Use bus space accessors instead of in*()/out*().
- Use callout(9) instead of timeout(9).
- Stop watchdog timer in detach and don't hold mutex across
  bus_teardown_intr().
- Use device_printf() and if_printf().
- De-spl().

Tested by:	no one