bios: Implement BIOSIntegerAttribute

Implement BIOSIntegerAttribute, most of the code is copied from
bios/bios_parser.cpp.

Implement SetAttrValueOnDbus and constructEntry for integer attribute

Signed-off-by: John Wang <wangzqbj@inspur.com>
Change-Id: I57d5b5dbcb74f9a404f5133426208f4c6851dea2
diff --git a/libpldmresponder/bios_config.cpp b/libpldmresponder/bios_config.cpp
index d5c39ba..90b2ad2 100644
--- a/libpldmresponder/bios_config.cpp
+++ b/libpldmresponder/bios_config.cpp
@@ -1,5 +1,6 @@
 #include "bios_config.hpp"
 
+#include "bios_integer_attribute.hpp"
 #include "bios_string_attribute.hpp"
 
 #include <fstream>
@@ -65,6 +66,9 @@
     load(jsonDir / stringJsonFile, [this](const Json& entry) {
         constructAttribute<BIOSStringAttribute>(entry);
     });
+    load(jsonDir / stringJsonFile, [this](const Json& entry) {
+        constructAttribute<BIOSIntegerAttribute>(entry);
+    });
 }
 
 void BIOSConfig::buildAndStoreAttrTables(const Table& stringTable)