V4L/DVB (9953): em28xx: Add suport for debugging AC97 anciliary chips

The em28xx driver can be coupled to an anciliary AC97 chip. This patch
allows read/write AC97 registers directly.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/include/linux/videodev2.h b/include/linux/videodev2.h
index 754c8d9..e31144d 100644
--- a/include/linux/videodev2.h
+++ b/include/linux/videodev2.h
@@ -1376,6 +1376,7 @@
 #define V4L2_CHIP_MATCH_HOST       0  /* Match against chip ID on host (0 for the host) */
 #define V4L2_CHIP_MATCH_I2C_DRIVER 1  /* Match against I2C driver ID */
 #define V4L2_CHIP_MATCH_I2C_ADDR   2  /* Match against I2C 7-bit address */
+#define V4L2_CHIP_MATCH_AC97       3  /* Match against anciliary AC97 chip */
 
 struct v4l2_register {
 	__u32 match_type; /* Match type */