[Build-System] Fix switch_packetizer headers and add it to the build.

src/include/switch.h

@@ -136,6 +136,7 @@
 #include "switch_core_event_hook.h"
 #include "switch_scheduler.h"
 #include "switch_config.h"
+#include "switch_packetizer.h"
 #include "switch_nat.h"
 #include "switch_odbc.h"
 #include "switch_json.h"

src/include/switch_packetizer.h

@@ -29,8 +29,6 @@
  *
  */
 
-#include <switch.h>
-
 #ifndef SWITCH_PACKETIZER_H
 #define SWITCH_PACKETIZER_H