In prm80 move misc.h include in prm80.c to prm80.h

Should fix compilation problem on Open BSD 6.9

rigs/prm80/prm80.c

@@ -32,7 +32,6 @@
 
 #include "hamlib/rig.h"
 #include "serial.h"
-#include "misc.h"
 #include "cal.h"
 #include "register.h"
 #include "idx_builtin.h"

rigs/prm80/prm80.h

@@ -23,6 +23,7 @@
 #define _PRM80_H 1
 
 #include <hamlib/rig.h>
+#include "misc.h"
 
 #define BACKEND_VER "20210416"