FBE for Pixel 2

Includes various minor fixes for building in Android 8 trees with r23+ tag

Update FBE extended header in libtar to version 2 and include the entire
ext4_encryption_policy structure now after translating the policy.

See this post for more details:
https://plus.google.com/u/1/+DeesTroy/posts/i33ygUi7tiu

Change-Id: I2af981e51f459b17fcd895fb8c2d3f6c8200e24b
diff --git a/libblkid/src/topology/md.c b/libblkid/src/topology/md.c
index 5eba947..c232197 100644
--- a/libblkid/src/topology/md.c
+++ b/libblkid/src/topology/md.c
@@ -17,6 +17,7 @@
 #include <string.h>
 #include <sys/ioctl.h>
 #include <sys/stat.h>
+#include <sys/sysmacros.h>
 #include <sys/types.h>
 #include <unistd.h>