viterbi decoder: separate viterbi implementations

reorganizes viterbi decoder source so that each implementation
resides in a separate file.

lib/viterbi_decoder/viterbi_decoder.h

@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2016 Bastian Bloessl <bloessl@ccs-labs.org>
+ *
+ * This program 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.
+ *
+ * This program 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 INCLUDED_IEEE802_11_VITERBI_DECODER_H
+#define INCLUDED_IEEE802_11_VITERBI_DECODER_H
+
+#ifdef IEEE80211_MSSE2
+#include "viterbi_decoder_x86.h"
+#else
+#include "viterbi_decoder_generic.h"
+#endif
+
+#endif /* INCLUDED_IEEE802_11_VITERBI_DECODER_H */