logging: switch to lg2

After switching to C++20, it is recommended to use `phosphor::lg2`
to format log, and the correct `CODE_LINE` and `CODE_FUNC` values
can be used in log tracking.

Tested: built phosphor-srvcfg-manager successfully and Unit Test
passes.

Signed-off-by: George Liu <liuxiwei@inspur.com>
Change-Id: Ib676a0d8082b0e3e72b51bd5115bf5b05599e6ec
diff --git a/inc/utils.hpp b/inc/utils.hpp
index 234124d..dd2124a 100644
--- a/inc/utils.hpp
+++ b/inc/utils.hpp
@@ -16,6 +16,7 @@
 #pragma once
 #include <boost/asio.hpp>
 #include <phosphor-logging/elog-errors.hpp>
+#include <phosphor-logging/lg2.hpp>
 #include <sdbusplus/asio/object_server.hpp>
 #include <xyz/openbmc_project/Common/error.hpp>