Parallelize Max (microsoft#16745)

It gives up to 7.5% improvement in LLaMA 7B case.

Author: yihonglyu

onnxruntime/core/providers/cpu/math/element_wise_ops.cc

@@ -855,7 +855,12 @@ struct Max_8::ComputeImpl {
         }};
 
     int input_count = inst.Node().InputArgCount().front();
-    UntypedBroadcastVariadic(input_count, *context, typed_allocator, funcs);
+    // TODO: Parallelize across spans in UntypedBroadcastVariadic to avoid specific logic here
+    if (input_count == 2) {
+      UntypedBroadcastTwo(*context, funcs, 1.0);
+    } else {
+      UntypedBroadcastVariadic(input_count, *context, typed_allocator, funcs);
+    }
 
     return Status::OK();
   }