Documentation: devices.txt: Remove ttySIOC*

IOC3 serial driver was removed, remove associated devices
from documentation.

Fixes: 9c860e4cf708 ("tty/serial: remove the ioc3_serial driver")
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Link: https://lore.kernel.org/r/f13b5c64f8cb6d8f2357d7be14397676b27ac2a2.1691992627.git.christophe.leroy@csgroup.eu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>