cmake: Fixes for qurt and nuttx

Added px4_parameters.c to nuttx executable src list.
Minor syntax fix in Tools/px_generate_params.py for semicolon.
Added handling of PX4_MAIN which was not yet supoprted in the
cmake build.
Fixed include quotes in muorb_test_example.cpp

Signed-off-by: Mark Charlebois <charlebm@gmail.com>

src/platforms/qurt/tests/muorb/muorb_test_example.cpp

@@ -45,7 +45,7 @@
 #include <string.h>
 #include "uORB/topics/sensor_combined.h"
 #include "uORB/topics/pwm_input.h"
-#include "uORB.h"
+#include "modules/uORB/uORB.h"
 #include "px4_middleware.h"
 #include "px4_defines.h"
 #include <stdlib.h>