Small cleanups

closes https://github.com/official-stockfish/Stockfish/pull/3301

No functional change

src/psqt.h

@@ -0,0 +1,38 @@
+/*
+  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
+  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+
+  Stockfish is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  Stockfish is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+
+#ifndef PSQT_H_INCLUDED
+#define PSQT_H_INCLUDED
+
+
+#include "types.h"
+
+
+namespace PSQT
+{
+
+extern Score psq[PIECE_NB][SQUARE_NB];
+
+// Fill psqt array from a set of internally linked parameters
+extern void init();
+
+} // namespace PSQT
+
+
+#endif // PSQT_H_INCLUDED