add clang-tidy

This commit implements a clang-tidy file, and makes some changes to get
it to pass.  Most changes are naming or mechanical in nature.

Tested:
Clang-tidy now passes.

Signed-off-by: Ed Tanous <ed@tanous.net>
Change-Id: Ia441e4801b6c8725421d160c531c5df141f255d4
diff --git a/src/PwmSensor.cpp b/src/PwmSensor.cpp
index 8993f2b..bd9c9d6 100644
--- a/src/PwmSensor.cpp
+++ b/src/PwmSensor.cpp
@@ -13,10 +13,8 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 */
-#include "PwmSensor.hpp"
-
-#include "Utils.hpp"
-
+#include <PwmSensor.hpp>
+#include <Utils.hpp>
 #include <sdbusplus/asio/object_server.hpp>
 
 #include <fstream>