reorder headers

Reordering all the headers to the following structure:

header file:
local
c
cpp (including openbmc libraries)

source file:
source.hpp (if applicable)
local
c
cpp

Change-Id: Ia74a5c761a3029819366159de3cfd40c5e4c4a2c
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/argument.cpp b/argument.cpp
index 603a54c..6d4bb1a 100644
--- a/argument.cpp
+++ b/argument.cpp
@@ -13,10 +13,11 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+#include "argument.hpp"
+
+#include <algorithm>
 #include <iostream>
 #include <iterator>
-#include <algorithm>
-#include "argument.hpp"
 
 namespace phosphor
 {