serial: uapi: Declare all userspace-visible io types

ioctl(TIOCGSERIAL|TIOCSSERIAL) report and can change the port->iotype.
UART drivers use the UPIO_* definitions, but the uapi header defines
parallel values and userspace uses these parallel values for ioctls;
thus the userspace values are definitive.

Define UPIO_* iotypes in terms of the uapi defines, SERIAL_IO_*;
extend the uapi defines to include all values in use by the serial
core.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>