docs: device-mapper: move it to the admin-guide

The DM support describes lots of aspects related to mapped
disk partitions from the userspace PoV.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

Documentation/device-mapper/index.rst → Documentation/admin-guide/device-mapper/index.rst

-:orphan:
-
 =============
 Device Mapper
 =============

Documentation/admin-guide/index.rst

@@ -80,6 +80,7 @@ configure specific aspects of kernel behavior to your liking.
    namespaces/index
    perf-security
    acpi/index
+   device-mapper/index
 
 .. only::  subproject and html
 

MAINTAINERS

@@ -4735,7 +4735,7 @@ Q:	http://patchwork.kernel.org/project/dm-devel/list/
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm.git
 T:	quilt http://people.redhat.com/agk/patches/linux/editing/
 S:	Maintained
-F:	Documentation/device-mapper/
+F:	Documentation/admin-guide/device-mapper/
 F:	drivers/md/Makefile
 F:	drivers/md/Kconfig
 F:	drivers/md/dm*

drivers/md/Kconfig

@@ -453,7 +453,7 @@ config DM_INIT
 	Enable "dm-mod.create=" parameter to create mapped devices at init time.
 	This option is useful to allow mounting rootfs without requiring an
 	initramfs.
-	See Documentation/device-mapper/dm-init.rst for dm-mod.create="..."
+	See Documentation/admin-guide/device-mapper/dm-init.rst for dm-mod.create="..."
 	format.
 
 	If unsure, say N.

drivers/md/dm-init.c

@@ -25,7 +25,7 @@ static char *create;
  * Format: dm-mod.create=<name>,<uuid>,<minor>,<flags>,<table>[,<table>+][;<name>,<uuid>,<minor>,<flags>,<table>[,<table>+]+]
  * Table format: <start_sector> <num_sectors> <target_type> <target_args>
  *
- * See Documentation/device-mapper/dm-init.rst for dm-mod.create="..." format
+ * See Documentation/admin-guide/device-mapper/dm-init.rst for dm-mod.create="..." format
  * details.
  */
 

drivers/md/dm-raid.c

@@ -3558,7 +3558,7 @@ static void raid_status(struct dm_target *ti, status_type_t type,
 		 * v1.5.0+:
 		 *
 		 * Sync action:
-		 *   See Documentation/device-mapper/dm-raid.rst for
+		 *   See Documentation/admin-guide/device-mapper/dm-raid.rst for
 		 *   information on each of these states.
 		 */
 		DMEMIT(" %s", sync_action);