media: docs: */media/index.rst: don't use ReST doc:`foo`

The :doc:`foo` tag is auto-generated via automarkup.py.
    So, use the filename at the sources, instead of :doc:`foo`.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

Documentation/admin-guide/media/index.rst

@@ -11,12 +11,14 @@ its supported drivers.
 
 Please see:
 
-- :doc:`/userspace-api/media/index`
-     for the userspace APIs used on media devices.
+Documentation/userspace-api/media/index.rst
 
-- :doc:`/driver-api/media/index`
-     for driver development information and Kernel APIs used by
-     media devices;
+  - for the userspace APIs used on media devices.
+
+Documentation/driver-api/media/index.rst
+
+  - for driver development information and Kernel APIs used by
+    media devices;
 
 The media subsystem
 ===================

Documentation/driver-api/media/index.rst

@@ -11,11 +11,13 @@ its supported drivers.
 
 Please see:
 
-- :doc:`/admin-guide/media/index`
-    for usage information about media subsystem and supported drivers;
+Documentation/admin-guide/media/index.rst
 
-- :doc:`/userspace-api/media/index`
-     for the userspace APIs used on media devices.
+  - for usage information about media subsystem and supported drivers;
+
+Documentation/userspace-api/media/index.rst
+
+  - for the userspace APIs used on media devices.
 
 
 .. only:: html

Documentation/userspace-api/media/index.rst

@@ -11,12 +11,14 @@ used by media devices.
 
 Please see:
 
-- :doc:`/admin-guide/media/index`
-    for usage information about media subsystem and supported drivers;
+Documentation/admin-guide/media/index.rst
 
-- :doc:`/driver-api/media/index`
-     for driver development information and Kernel APIs used by
-     media devices;
+  - for usage information about media subsystem and supported drivers;
+
+Documentation/driver-api/media/index.rst
+
+  - for driver development information and Kernel APIs used by
+    media devices;
 
 
 .. only:: html