[media] bttv: add VIDIOC_DBG_G_CHIP_IDENT

VIDIOC_DBG_G_CHIP_IDENT is a prerequisite for the G/S_REGISTER ioctls.
In addition, add support to call G/S_REGISTER for supporting i2c devices.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/pci/bt8xx/bttv.h b/drivers/media/pci/bt8xx/bttv.h
index 79a1124..6139ce2 100644
--- a/drivers/media/pci/bt8xx/bttv.h
+++ b/drivers/media/pci/bt8xx/bttv.h
@@ -359,6 +359,9 @@
 #define bttv_call_all(btv, o, f, args...) \
 	v4l2_device_call_all(&btv->c.v4l2_dev, 0, o, f, ##args)
 
+#define bttv_call_all_err(btv, o, f, args...) \
+	v4l2_device_call_until_err(&btv->c.v4l2_dev, 0, o, f, ##args)
+
 extern int bttv_I2CRead(struct bttv *btv, unsigned char addr, char *probe_for);
 extern int bttv_I2CWrite(struct bttv *btv, unsigned char addr, unsigned char b1,
 			 unsigned char b2, int both);