Added "GET /2/dmi" API endpoint.

src/hw/dmi/DmiBoard.h

@@ -42,6 +42,10 @@ public:
 
     void decode(dmi_header *h);
 
+#   ifdef XMRIG_FEATURE_API
+    rapidjson::Value toJSON(rapidjson::Document &doc) const;
+#   endif
+
 private:
     String m_product;
     String m_vendor;