Workaround some broken BIOSes that specify edge-sensitive but active-low
settings for ACPI-enumerated serial ports by forcing any IRQs that use
an ISA IRQ value with these settings to active-high instead of active-low.

This is known to occur with the BIOS on an Intel D2500CCE motherboard.

Tested by:	Robert Ames <robertames@hotmail.com>, lev
Submitted by:	Juergen Weiss weiss at uni-mainz.de (original patch)