soc/intel/baytrail: Adjust status of IOSF ACPI object

Neither Windows nor mainline Linux make use of IOSF on the Baytrail
platform, so adjust the ACPI status return value based on
CONFIG(CHROMEOS) to prevent an unknown device being listed in Windows
device manager.

TEST=build/boot Win11, Linux 6.2 on google/swanky

Change-Id: I249028c57cc704955cf5a11e2088780ef58e16cf
Signed-off-by: Matt DeVillier <matt.devillier@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/77141
Reviewed-by: Sean Rhodes <sean@starlabs.systems>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/soc/intel/baytrail/acpi/southcluster.asl b/src/soc/intel/baytrail/acpi/southcluster.asl
index 131825e..9f3c76f 100644
--- a/src/soc/intel/baytrail/acpi/southcluster.asl
+++ b/src/soc/intel/baytrail/acpi/southcluster.asl
@@ -240,6 +240,15 @@
 		RBAS = CONFIG_ECAM_MMCONF_BASE_ADDRESS + 0xD0
 		Return (^RBUF)
 	}
+
+	Method (_STA)
+	{
+#if CONFIG(CHROMEOS)
+		Return (0xF)
+#else
+		Return (0x0)
+#endif
+	}
 }
 
 /* LPC Bridge 0:1f.0 */