Make run faster on ARM CPUs using fast math approximation

Use --fast-math to use sine/cosine tables and approximate atan2.

src/tv/main.c

@@ -473,6 +473,9 @@ int main(int argc, char *argv[])
 		exit(0);
 	}
 
+	/* inits */
+	fm_init(0);
+
 	if (!wave_file) {
 #ifdef HAVE_SDR
 		rc = sdr_configure(samplerate);
@@ -499,6 +502,9 @@ int main(int argc, char *argv[])
 		return -EINVAL;
 	}
 
+	/* exits */
+	fm_exit();
+
 	return 0;
 }