prefer std::format over fmt

Switch to std::format to remove the dependency on fmt.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Id3a1295ba8a90fb756cfc500892dcc5b3235e27b
diff --git a/occ_pass_through.hpp b/occ_pass_through.hpp
index f11695c..3cc462b 100644
--- a/occ_pass_through.hpp
+++ b/occ_pass_through.hpp
@@ -4,13 +4,12 @@
 #include "powermode.hpp"
 #include "utils.hpp"
 
-#include <fmt/core.h>
-
 #include <org/open_power/OCC/PassThrough/server.hpp>
 #include <phosphor-logging/log.hpp>
 #include <sdbusplus/bus.hpp>
 #include <sdbusplus/server/object.hpp>
 
+#include <format>
 #include <string>
 
 namespace open_power