added log to calculate database probing time

fixing LeelaChessZero#1768
we brought one

src/syzygy/syzygy.cc

@@ -1406,9 +1406,13 @@ class SyzygyTablebaseImpl {
       }
       idx = type != DTM ? encode_pawn_f(p, ei, be) : encode_pawn_r(p, ei, be);
     }
-
+    auto start = std::chrono::high_resolution_clock::now();
     uint8_t* w = decompress_pairs(ei->precomp, idx);
-
+    auto end = std::chrono::high_resolution_clock::now();
+    auto duration = std::chrono::duration_cast<std::chrono::microseconds>(end - start);
+    if (duration.count() > 1) {
+      std::cout << "Time taken: " << duration.count() << " microseconds" << std::endl;
+    }
     if (type == WDL) return static_cast<int>(w[0]) - 2;
 
     int v = w[0] + ((w[1] & 0x0f) << 8);