[media] soc-camera: Add and use soc_camera_power_[on|off]() helper functions

Instead of forcing all soc-camera drivers to go through the mid-layer to
handle power management, create soc_camera_power_[on|off]() functions
that can be called from the subdev .s_power() operation to manage
regulators and platform-specific power handling. This allows non
soc-camera hosts to use soc-camera-aware clients.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
[g.liakhovetski@gmx.de: fix compile breakage]
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/i2c/soc_camera/ov6650.c b/drivers/media/i2c/soc_camera/ov6650.c
index 3e028b1..12d57a5 100644
--- a/drivers/media/i2c/soc_camera/ov6650.c
+++ b/drivers/media/i2c/soc_camera/ov6650.c
@@ -432,6 +432,14 @@
 }
 #endif
 
+static int ov6650_s_power(struct v4l2_subdev *sd, int on)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(sd);
+	struct soc_camera_link *icl = soc_camera_i2c_to_link(client);
+
+	return soc_camera_set_power(&client->dev, icl, on);
+}
+
 static int ov6650_g_crop(struct v4l2_subdev *sd, struct v4l2_crop *a)
 {
 	struct i2c_client *client = v4l2_get_subdevdata(sd);
@@ -866,6 +874,7 @@
 	.g_register		= ov6650_get_register,
 	.s_register		= ov6650_set_register,
 #endif
+	.s_power		= ov6650_s_power,
 };
 
 /* Request bus settings on camera side */