libpldmresponder: implement handler for GetPDR

This commit implements the GetPDR command as defined in DSP0248 v1.1.1.
Multipart PDR transfers are still not implemented.

Signed-off-by: Deepak Kodihalli <dkodihal@in.ibm.com>
Change-Id: Ic520a914e8228b723521151f4ba1eed947179047
diff --git a/libpldmresponder/platform.hpp b/libpldmresponder/platform.hpp
new file mode 100644
index 0000000..253d786
--- /dev/null
+++ b/libpldmresponder/platform.hpp
@@ -0,0 +1,26 @@
+#pragma once
+
+#include <stdint.h>
+
+#include <vector>
+
+#include "libpldm/platform.h"
+
+namespace pldm
+{
+
+using Response = std::vector<uint8_t>;
+
+namespace responder
+{
+
+/** @brief Handler for GetPDR
+ *
+ *  @param[in] request - Request message payload
+ *  @param[in] payloadLength - Request payload length
+ *  @param[out] Response - Response message written here
+ */
+Response getPDR(const pldm_msg* request, size_t payloadLength);
+
+} // namespace responder
+} // namespace pldm