tty: iuu_phoenix: fix locking.

Bring in the relevant bits of the 0.9 vendor driver.

Signed-off-by: Olivier Bornet <Olivier.Bornet@puck.ch>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 file changed