split the commands out

Split the commands out to avoid conflicts in multiple definitions of
IPMI_CC_OK, etc, in a different environment.

Signed-off-by: Patrick Venture <venture@google.com>
Change-Id: I1f3a0214b4f6f6417a5649b0fc2d297119f8ad88
diff --git a/psu.cpp b/psu.cpp
index 3876fcf..d3ded47 100644
--- a/psu.cpp
+++ b/psu.cpp
@@ -16,9 +16,9 @@
 
 #include "psu.hpp"
 
+#include "commands.hpp"
 #include "errors.hpp"
 #include "handler.hpp"
-#include "ipmi.hpp"
 
 #include <cstdint>
 #include <cstring>