sdbusplus: replace message::variant with std::variant

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I8c5f1951104be5a847cb054670f9b5018925c72c
diff --git a/evdev.hpp b/evdev.hpp
index eb7781b..b5d1394 100644
--- a/evdev.hpp
+++ b/evdev.hpp
@@ -52,7 +52,7 @@
 {
 
     using Property = std::string;
-    using Value = sdbusplus::message::variant<bool, std::string>;
+    using Value = std::variant<bool, std::string>;
     // Association between property and its value
     using PropertyMap = std::map<Property, Value>;
     using Interface = std::string;