Revert r233662 and generalize the hack.  Writing zero to BAR actually does not disable it and it is even harmful as hselasky found out.  Historically, this code was originated from (OLDCARD) CardBus driver and later leaked into PCI driver when CardBus was newbus'ified and refactored with PCI driver. However, it is not really necessary even for CardBus.
Revert r233662 and generalize the hack.  Writing zero to BAR actually does
not disable it and it is even harmful as hselasky found out.  Historically,
this code was originated from (OLDCARD) CardBus driver and later leaked into
PCI driver when CardBus was newbus'ified and refactored with PCI driver.
However, it is not really necessary even for CardBus.

Reviewed by:	hselasky, imp, jhb

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase