Label goldfish block devices with their own types.

This assigns block device types as per device/generic/goldfish/fstab.goldfish.
Eliminates (permissive) avc:  denied messages for fsck.

Change-Id: Ia72bdfb16975f051548b6b2c0636e4f907295789
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
diff --git a/target/board/generic/sepolicy/file_contexts b/target/board/generic/sepolicy/file_contexts
index bbc34af..444a47f 100644
--- a/target/board/generic/sepolicy/file_contexts
+++ b/target/board/generic/sepolicy/file_contexts
@@ -1,3 +1,6 @@
+/dev/block/mtdblock0       u:object_r:system_block_device:s0
+/dev/block/mtdblock1       u:object_r:userdata_block_device:s0
+/dev/block/mtdblock2       u:object_r:cache_block_device:s0
 /dev/qemu_.*		u:object_r:qemu_device:s0
 /dev/socket/qemud	u:object_r:qemud_socket:s0
 /system/bin/qemud	u:object_r:qemud_exec:s0