SIO2K serial drivers

The combination of a SMsC SuperIO chip on an SMP system could cause a

lockup when a port is opened. This problem has been corrected.

SuperIO and UltraIO are motherboard chip sets with serial ports, often

with the capability for extented bit rates.

Added support for the following SMsC SuperIO and UltraIO chips with bit

rates up to 460800: FDC37N971, FDC37N972, FDC37M70x, FDC37M81x, FDC37N958,

FDC37N769, FDC37N3869, LPC47N227, LPC47N252, LPC47N267, LPC47M192,

LPC47M14x, LPC47M10x, LPC47S45x, FDC37C67x, FDC37M70x, FDC37B72x, and

FDC37B77x.

Added support for up to 921600 bps for the following Winbond SuperIO

chips: W83977EF and W83977TF.

YOU MUST add "SuperIO", without the quote marks, to the uart.sys command

line to enable the higher bit rates on your computer.

A problem was corrected in sio2k.sys that could cause a trap when exiting

from PMLM.