px4fmu-v5: Upstream NuttX up_cxxinitialize moved

was:<nuttx/arch.h> is:platform/cxxinitialize.h
   Removed PX4 version:src/modules/systemlib/up_cxxinitialize.c
   in favor of nuttx platform/gnu/gnu_cxxinitialize.c

src/drivers/boards/px4fmu-v5/px4fmu_init.c

@@ -55,7 +55,7 @@
 #include <debug.h>
 #include <errno.h>
 
-#include <nuttx/arch.h>
+#include "platform/cxxinitialize.h"
 #include <nuttx/board.h>
 #include <nuttx/spi/spi.h>
 #include <nuttx/i2c/i2c_master.h>