M17 mod/demod: moved m17 specific code to a new modems library

modems/m17/Correlator.cpp

@@ -0,0 +1,9 @@
+#include "Correlator.h"
+
+namespace mobilinkd {
+
+// IIR with Nyquist of 1/240.
+const std::array<float,3> Correlator::b = {4.24433681e-05, 8.48867363e-05, 4.24433681e-05};
+const std::array<float,3> Correlator::a = {1.0, -1.98148851,  0.98165828};
+
+} // namespace mobilinkd