google-ipmi-sys: Refactor to use new version of OEM IPMI Handler

Using the new version of ipmi handler provide a higher level wrapper
over the same functionalities. It helps us parse the input and output to
have more control of the input/output we see.

The input and output will be
`std::uint8_t, std::optional<std::vector<uint8_t>>`.

This represents `subcommand` and any input data.

Changes to note,
- all subcommand in the request/response struct are removed. It will be
  managed by the wrapper directly.
    - Unit tests checking for input with only the subcommand are
      removed.
- Move all reply struct to header files to be accessible in unit test.

Tested:
All IPMI OEM command still works the same as before this change.

Change-Id: I4230ab84a497a867248fe82224e32cc69b314b64
Signed-off-by: Willy Tu <wltu@google.com>
diff --git a/cpld.hpp b/cpld.hpp
index 688fb54..84db3ba 100644
--- a/cpld.hpp
+++ b/cpld.hpp
@@ -18,14 +18,25 @@
 
 #include <ipmid/api.h>
 
+#include <ipmid/api-types.hpp>
+#include <vector>
+
 namespace google
 {
 namespace ipmi
 {
 
+struct CpldReply
+{
+    uint8_t major;
+    uint8_t minor;
+    uint8_t point;
+    uint8_t subpoint;
+} __attribute__((packed));
+
 // 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);
+Resp cpldVersion(const std::vector<std::uint8_t>& data,
+                 const HandlerInterface* handler);
 
 } // namespace ipmi
 } // namespace google