V4L/DVB (4387): Add Kconfig infrastructure for dvb_attach

Allow it to be en/disabled
Disable it in < 2.6.17 due to symbol_xxx() bug

Signed-off-by: Andrew de Quincey <adq_dvb@lidskialf.net>
Acked-by: Michael Krufky <mkrufky@linuxtv.org>
Acked-by: Trent Piepho <xyzzy@speakeasy.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
diff --git a/drivers/media/dvb/frontends/cx24123.h b/drivers/media/dvb/frontends/cx24123.h
index 9606f82..6a8cb4c 100644
--- a/drivers/media/dvb/frontends/cx24123.h
+++ b/drivers/media/dvb/frontends/cx24123.h
@@ -32,7 +32,16 @@
 	int (*set_ts_params)(struct dvb_frontend* fe, int is_punctured);
 };
 
+#if defined(CONFIG_DVB_CX24123) || defined(CONFIG_DVB_CX24123_MODULE)
 extern struct dvb_frontend* cx24123_attach(const struct cx24123_config* config,
 					   struct i2c_adapter* i2c);
+#else
+static inline struct dvb_frontend* cx24123_attach(const struct cx24123_config* config,
+						  struct i2c_adapter* i2c)
+{
+	printk(KERN_WARNING "%s: driver disabled by Kconfig\n", __FUNCTION__);
+	return NULL;
+}
+#endif // CONFIG_DVB_CX24123
 
 #endif /* CX24123_H */