clang-format: update to latest from docs repo

The openbmc/docs/style/cpp/.clang-format has been updated to support
clang-format10, take this opportunity to update it in this repo.

Change-Id: I9e6b9853bf4cd7399b1ae504ea3be5093d763fee
Signed-off-by: Adriana Kobylak <anoo@us.ibm.com>
21 files changed