cmake remove circular linking and reorganize

- px4_add_module now requires MAIN
 - px4_add_library doesn't automatically link

src/examples/matlab_csv_serial/CMakeLists.txt

@@ -37,6 +37,4 @@ px4_add_module(
 	SRCS
 		matlab_csv_serial.c
 	DEPENDS
-		platforms__common
 	)
-# vim: set noet ft=cmake fenc=utf-8 ff=unix : 

src/examples/matlab_csv_serial/matlab_csv_serial.c

@@ -58,7 +58,7 @@
 #include <uORB/uORB.h>
 #include <drivers/drv_accel.h>
 #include <drivers/drv_gyro.h>
-#include <systemlib/perf_counter.h>
+#include <perf/perf_counter.h>
 #include <systemlib/systemlib.h>
 #include <systemlib/err.h>
 #include <poll.h>