Support int32 property variant type

Change-Id: I19d426e00b4ce1cb31d4dbc428caa5749e012322
Signed-off-by: Matthew Barth <msbarth@us.ibm.com>
diff --git a/control/types.hpp b/control/types.hpp
index 000eec0..9b65c5f 100644
--- a/control/types.hpp
+++ b/control/types.hpp
@@ -32,6 +32,7 @@
                              std::vector<ConditionProperty>>;
 
 using PropertyVariantType = sdbusplus::message::variant<bool,
+                                                        int32_t,
                                                         int64_t,
                                                         std::string>;