POSIX and QuRT: fixed calls needing px4_ prefix

There were some missed calls to open and ioctl that need to be
px4_open and px4_ioctl.

QuRT also does not provide usleep() so px4_time.h has to be included
in files calling usleep.

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

src/modules/simulator/simulator.cpp

@@ -38,6 +38,7 @@
 
 #include <px4_debug.h>
 #include <px4_tasks.h>
+#include <px4_time.h>
 #include <systemlib/err.h>
 #include <errno.h>
 #include <stdio.h>