md/dm-raid: DM_RAID should select MD_RAID10

Now that DM_RAID supports raid10, it needs to select that code
to ensure it is included.

Cc: Jonathan Brassow <jbrassow@redhat.com>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>

drivers/md/Kconfig

@@ -277,13 +277,14 @@ config DM_MIRROR
          needed for live data migration tools such as 'pvmove'.
 
 config DM_RAID
-       tristate "RAID 1/4/5/6 target"
+       tristate "RAID 1/4/5/6/10 target"
        depends on BLK_DEV_DM
        select MD_RAID1
+       select MD_RAID10
        select MD_RAID456
        select BLK_DEV_MD
        ---help---
-	 A dm target that supports RAID1, RAID4, RAID5 and RAID6 mappings
+	 A dm target that supports RAID1, RAID10, RAID4, RAID5 and RAID6 mappings
 
 	 A RAID-5 set of N drives with a capacity of C MB per drive provides
 	 the capacity of C * (N - 1) MB, and protects against a failure