initial import of Osmocom TETRA phy and lower MAC code

src/lower_mac/tetra_rm3014.h

@@ -0,0 +1,16 @@
+#ifndef TETRA_RM3014_H
+#define TETRA_RM3014_H
+
+#include <stdint.h>
+
+void tetra_rm3014_init(void);
+uint32_t tetra_rm3014_compute(const uint16_t in);
+
+/**
+ * Decode @param inp to @param out and return if there was
+ * an error in the input. In the future this should correct
+ * the error or such.
+ */
+int tetra_rm3013_decode(const uint32_t inp, uint16_t *out);
+
+#endif