When we added support for nested (stage 1 + stage 2) translation
to the SMMU in commit 58377c363291d we forgot to update the
comment that documents the valid values of the "stage" property.
Add the new "nested" value to it.

Fixes: 58377c363291d ("hw/arm/smmuv3: Support and advertise nesting")
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 hw/arm/smmuv3.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/hw/arm/smmuv3.c b/hw/arm/smmuv3.c
index 39719763897..4c49b5a885f 100644
--- a/hw/arm/smmuv3.c
+++ b/hw/arm/smmuv3.c
@@ -1981,6 +1981,7 @@ static Property smmuv3_properties[] = {
      * Stages of translation advertised.
      * "1": Stage 1
      * "2": Stage 2
+     * "nested": Both stage 1 and stage 2
      * Defaults to stage 1
      */
     DEFINE_PROP_STRING("stage", SMMUv3State, stage),
-- 
2.34.1