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/power-supply/power_supply.cpp b/power-supply/power_supply.cpp
index 195e750..be89ed3 100644
--- a/power-supply/power_supply.cpp
+++ b/power-supply/power_supply.cpp
@@ -638,8 +638,7 @@
                             : "");
             }
             catch (ReadFailure& e)
-            {
-            }
+            {}
         }
     }