target/arm/arm-powerctl: Fix psci info return values

The power state spec section 5.1.5 AFFINITY_INFO defines the
affinity info return values as

  0 ON
  1 OFF
  2 ON_PENDING

I grepped QEMU for power_state to ensure that no assumptions
of OFF=0 were being made.
Signed-off-by: NAndrew Jones <drjones@redhat.com>
Message-id: 20170303123232.4967-1-drjones@redhat.com
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

target/arm/cpu.h

@@ -536,8 +536,8 @@ typedef void ARMELChangeHook(ARMCPU *cpu, void *opaque);
 /* These values map onto the return values for
  * QEMU_PSCI_0_2_FN_AFFINITY_INFO */
 typedef enum ARMPSCIState {
-    PSCI_OFF = 0,
-    PSCI_ON = 1,
+    PSCI_ON = 0,
+    PSCI_OFF = 1,
     PSCI_ON_PENDING = 2
 } ARMPSCIState;