drm/radeon/kms: set i2c adapter class to I2C_CLASS_DDC

The most common use of the radeon i2c buses is for ddc.
Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/radeon/radeon_i2c.c

@@ -888,6 +888,7 @@ struct radeon_i2c_chan *radeon_i2c_create(struct drm_device *dev,
 
 	i2c->rec = *rec;
 	i2c->adapter.owner = THIS_MODULE;
+	i2c->adapter.class = I2C_CLASS_DDC;
 	i2c->dev = dev;
 	i2c_set_adapdata(&i2c->adapter, i2c);
 	if (rec->mm_i2c ||
@@ -947,6 +948,7 @@ struct radeon_i2c_chan *radeon_i2c_create_dp(struct drm_device *dev,
 
 	i2c->rec = *rec;
 	i2c->adapter.owner = THIS_MODULE;
+	i2c->adapter.class = I2C_CLASS_DDC;
 	i2c->dev = dev;
 	snprintf(i2c->adapter.name, sizeof(i2c->adapter.name),
 		 "Radeon aux bus %s", name);