Move bswap.h to include/qemu/bswap.h

Before integrating upstream patches, we need to move source
files around to match the new directory structure used there.
This is the first of such changes.

Change-Id: Ib42669003851aa5a5295dd66cfebb307c63f054f
diff --git a/android/snapshot.c b/android/snapshot.c
index d02d9a8..93ac1b6 100644
--- a/android/snapshot.c
+++ b/android/snapshot.c
@@ -33,7 +33,7 @@
 #include <time.h>
 #include <unistd.h>
 
-#include "bswap.h"
+#include "qemu/bswap.h"
 #include "android/utils/debug.h"
 #include "android/utils/system.h"
 #include "android/snapshot.h"