backends: Clean up includes

Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.

This commit was created with scripts/clean-includes.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1454089805-5470-5-git-send-email-peter.maydell@linaro.org
diff --git a/backends/rng-egd.c b/backends/rng-egd.c
index 6c13409..2de5cd5 100644
--- a/backends/rng-egd.c
+++ b/backends/rng-egd.c
@@ -10,6 +10,7 @@
  * See the COPYING file in the top-level directory.
  */
 
+#include "qemu/osdep.h"
 #include "sysemu/rng.h"
 #include "sysemu/char.h"
 #include "qapi/qmp/qerror.h"