Char: mxser, add support for CP-114UL

Add new card (0x1393:0x1143) support added in 1.11 original driver, also
allow rate change in set_serial_info ioctl (as per 1.11 too).

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