[media] media framework: rename pads init function to media_entity_pads_init()

With the MC next gen rework, what's left for media_entity_init()
is to just initialize the PADs. However, certain devices, like
a FLASH led/light doesn't have any input or output PAD.

So, there's no reason why calling media_entity_init() would be
mandatory. Also, despite its name, what this function actually
does is to initialize the PADs data. So, rename it to
media_entity_pads_init() in order to reflect that.

The media entity actual init happens during entity register,
at media_device_register_entity(). We should move init of
num_links and num_backlinks to it.

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/media/i2c/adp1653.c

@@ -512,7 +512,7 @@ static int adp1653_probe(struct i2c_client *client,
 	if (ret)
 		goto free_and_quit;
 
-	ret = media_entity_init(&flash->subdev.entity, 0, NULL);
+	ret = media_entity_pads_init(&flash->subdev.entity, 0, NULL);
 	if (ret < 0)
 		goto free_and_quit;