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/ec_fixme.go

@@ -6,7 +6,7 @@ func FIXMEEC(ctx Context) {
 	ap := Create(ctx, "acpi/platform.asl")
 	defer ap.Close()
 
-	hasKeyboard := IsIOPortUsedBy(ctx, 0x60, "keyboard")
+	hasKeyboard := ctx.InfoSource.HasPS2()
 
 	sbGPE := GuessECGPE(ctx)
 	var GPEUnsure bool