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pc, pc64: revert addition of pcireset() call to pcicfginit()

Revert the change, as it causes system lockups on bootup
on some systems with USB OHCI controllers, suspected to be
caused by BIOS/SMM accessing the device as BIOS handover
has not been executed yet.

We might bring that back when the problem has is better
understood.

--- a/sys/src/9/pc/pcipc.c

+++ b/sys/src/9/pc/pcipc.c

@@ -716,7 +716,15 @@

 	if(pciroot == nil)

 		goto out;

-	pcireset();

+	/*

+	 * Disabling devices here (by clearing bus master enable)

+	 * causes problems with with some OHCI USB controllers.

+	 * I supected that this is due to legacy device emulation

+	 * and revoking bus master flag before executing the handoff

+	 * makes BIOS/SMM lock up the system.

+	 *

+	 * pcireset();

+	 */

 	if(nobios) {

 		uvlong mema;