remove usage of sdbusplus::message::variant

sdbusplus has had its alias of std::variant in place for long
enough. This changes all ipmid references to use std::variant
directly instead of the sdbusplus alias.

Tested-by: building and running ipmid

Change-Id: Id5b4136d4589aa598815edd3ef4202e64a7698e2
Signed-off-by: Vernon Mauery <vernon.mauery@linux.intel.com>
diff --git a/selutility.hpp b/selutility.hpp
index b21081a..bf16a5c 100644
--- a/selutility.hpp
+++ b/selutility.hpp
@@ -28,8 +28,8 @@
 using Timestamp = uint64_t;
 using Message = std::string;
 using AdditionalData = std::vector<std::string>;
-using PropertyType = sdbusplus::message::variant<Resolved, Id, Timestamp,
-                                                 Message, AdditionalData>;
+using PropertyType =
+    std::variant<Resolved, Id, Timestamp, Message, AdditionalData>;
 
 static constexpr auto selVersion = 0x51;
 static constexpr auto invalidTimeStamp = 0xFFFFFFFF;