cmake remove circular linking and reorganize

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

src/drivers/rgbled_pwm/CMakeLists.txt

@@ -30,14 +30,12 @@
 # POSSIBILITY OF SUCH DAMAGE.
 #
 ############################################################################
+
 px4_add_module(
 	MODULE drivers__rgbled_pwm
 	MAIN rgbled_pwm
-	COMPILE_FLAGS
 	SRCS
 		rgbled_pwm.cpp
 	DEPENDS
-		platforms__common
-		lib__led
-	)
-# vim: set noet ft=cmake fenc=utf-8 ff=unix :
+		led
+	)

src/drivers/rgbled_pwm/rgbled_pwm.cpp

@@ -56,7 +56,7 @@
 #include <nuttx/wqueue.h>
 #include <drivers/drv_hrt.h>
 
-#include <systemlib/perf_counter.h>
+#include <perf/perf_counter.h>
 #include <systemlib/err.h>
 #include <systemlib/systemlib.h>