cmake remove circular linking and reorganize

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

src/drivers/batt_smbus/CMakeLists.txt

@@ -37,5 +37,4 @@ px4_add_module(
 	SRCS
 		batt_smbus.cpp
 	DEPENDS
-		platforms__common
 	)

src/drivers/batt_smbus/batt_smbus.cpp

@@ -51,7 +51,7 @@
 #include <drivers/drv_hrt.h>
 #include <px4_config.h>
 #include <px4_workqueue.h>
-#include <systemlib/perf_counter.h>
+#include <perf/perf_counter.h>
 #include <uORB/topics/battery_status.h>
 #include <uORB/topics/subsystem_info.h>
 #include <uORB/uORB.h>