Add .clang-format to repo for automated style

Add .clang-format to repo for automated style.  A consistent style
across Openbmc makes the code easier to read and edit.

Change-Id: I7c09792d2482f0be3e01776804347700f3e3e651
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/args.hpp b/args.hpp
index ee82986..02afc67 100644
--- a/args.hpp
+++ b/args.hpp
@@ -2,6 +2,7 @@
 
 #include <string>
 #include <unordered_map>
+#include <vector>
 
 namespace openpower
 {
@@ -10,8 +11,7 @@
 namespace args
 {
 
-using Args = std::unordered_map<std::string,
-      std::vector<std::string>>;
+using Args = std::unordered_map<std::string, std::vector<std::string>>;
 
 /** @brief Command-line argument parser for openpower-read-vpd
  *