CMakeLists: Update to clang format version 12

CMakeLists.txt

@@ -780,7 +780,7 @@ endif()
 # against all the src files. This should be used before making a pull request.
 # =======================================================================
 
-set(CLANG_FORMAT_POSTFIX "-10")
+set(CLANG_FORMAT_POSTFIX "-12")
 find_program(CLANG_FORMAT
     NAMES clang-format${CLANG_FORMAT_POSTFIX}
           clang-format