autoport: Improve keyboard detection.

Previously I tried to see if Linux think that port 0x60 is in use by keyboard.
Unfortunately it always thinks that it is. Instead just base off real input
busses used.

Change-Id: I4bb744938f623d29f38396165a1694fee78c3d32
Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-on: http://review.coreboot.org/10376
Tested-by: build bot (Jenkins)
Reviewed-by: Edward O'Callaghan <edward.ocallaghan@koparo.com>

util/autoport/main.go

@@ -59,6 +59,7 @@ type DevReader interface {
 	GetCPUModel() []uint32
 	GetEC() []byte
 	GetIOPorts() []IOPorts
+	HasPS2() bool
 }
 
 type IOPorts struct {