Refactor: rename namespace witherspoon to phosphor

This repo now becomes phosphor-power, rename namespace witherspoon to
phosphor to make it generic.

Signed-off-by: Lei YU <mine260309@gmail.com>
Change-Id: Icb9f8a7c33065add99f2bf42ed55745a28fa0424
diff --git a/names_values.hpp b/names_values.hpp
index c33c507..962c65d 100644
--- a/names_values.hpp
+++ b/names_values.hpp
@@ -2,7 +2,7 @@
 #include <sstream>
 #include <string>
 
-namespace witherspoon
+namespace phosphor
 {
 namespace power
 {
@@ -107,4 +107,4 @@
 
 } // namespace util
 } // namespace power
-} // namespace witherspoon
+} // namespace phosphor