clang updates

The openbmc CI was recently updated to clang-12 which requires some
formatting updates to the code:
https://github.com/openbmc/openbmc-build-scripts/commit/4569bf49daaebff06be0482426908bb5497fad08

Make those updates and refresh the clang-format file with the one from
docs:
https://github.com/openbmc/docs/blob/master/style/cpp/.clang-format

Change-Id: Ieb3626526373a053ec84431e7560003f229f338d
Signed-off-by: Adriana Kobylak <anoo@us.ibm.com>
diff --git a/phosphor-regulators/src/config_file_parser_error.hpp b/phosphor-regulators/src/config_file_parser_error.hpp
index 28db75a..9c783c5 100644
--- a/phosphor-regulators/src/config_file_parser_error.hpp
+++ b/phosphor-regulators/src/config_file_parser_error.hpp
@@ -49,8 +49,7 @@
                                    const std::string& error) :
         pathName{pathName},
         error{"ConfigFileParserError: " + pathName.string() + ": " + error}
-    {
-    }
+    {}
 
     /**
      * Returns the configuration file path name.