Documentation: devices.txt: Remove ttyIOC*

IOC4 serial driver was removed, remove associated devices
from documentation.

Fixes: a017ef17 ("tty/serial: remove the ioc4_serial driver")
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Link: https://lore.kernel.org/r/b5deb1222eb92017f0efe5b5cae127ac11983b3d.1691992627.git.christophe.leroy@csgroup.eu


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>