split out handler implementation from interface

Split out the handler object definition from the interface and drop the
default parameters.

Signed-off-by: Patrick Venture <venture@google.com>
Change-Id: Ie8c9dbf7881bbe6b5af3596a60430e3b3d573762
diff --git a/cpld.hpp b/cpld.hpp
index 5c747ed..4c8e059 100644
--- a/cpld.hpp
+++ b/cpld.hpp
@@ -11,8 +11,7 @@
 
 // Given a cpld identifier, return a version if available.
 ipmi_ret_t cpldVersion(const uint8_t* reqBuf, uint8_t* replyBuf,
-                       size_t* dataLen,
-                       const HandlerInterface* handler = &handlerImpl);
+                       size_t* dataLen, const HandlerInterface* handler);
 
 } // namespace ipmi
 } // namespace google