[media] media-entity.h: rename entity.type to entity.function

Entities should have one or more functions. Calling it as a
type proofed to not be correct, as an entity could eventually
have more than one type.

So, rename the field as function.

Please notice that this patch doesn't extend support for
multiple function entities. Such change will happen when
we have real case drivers using it.

No functional changes.

Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
diff --git a/Documentation/video4linux/v4l2-framework.txt b/Documentation/video4linux/v4l2-framework.txt
index 109cc37..2e0fc28 100644
--- a/Documentation/video4linux/v4l2-framework.txt
+++ b/Documentation/video4linux/v4l2-framework.txt
@@ -303,8 +303,8 @@
 	err = media_entity_init(&sd->entity, npads, pads);
 
 The pads array must have been previously initialized. There is no need to
-manually set the struct media_entity type and name fields, but the revision
-field must be initialized if needed.
+manually set the struct media_entity function and name fields, but the
+revision field must be initialized if needed.
 
 A reference to the entity will be automatically acquired/released when the
 subdev device node (if any) is opened/closed.