ext: Remove std::binary_function from DramPower

`std::binary_function` was deprecated in C++11 and officially
removed in CPP-17.

This caused a compilation error on some systems. Fortunately it can be
safely removed. It was unecessary. The commandItemSorter was compliant
witih the `sort` regardless.

Change-Id: I0d910e50c51cce2545dd89f618c99aef0fe8ab79

ext/drampower/src/CmdScheduler.h

@@ -84,8 +84,7 @@ class cmdScheduler {
     std::string  name;
     physicalAddr PhysicalAddr;
     // sorting the commands according to their scheduling time.
-    struct commandItemSorter : public std::binary_function<commandItem&,
-                                                           commandItem&, bool>{
+    struct commandItemSorter {
       bool operator()(const commandItem& lhs,
                       const commandItem& rhs) const
       {