[media] dvb-frontends: use IS_ENABLED

Instead of checking everywhere there for 3 symbols, use instead
IS_ENABLED macro.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/dvb-frontends/cx24123.h b/drivers/media/dvb-frontends/cx24123.h
index 51ae866..102e70d 100644
--- a/drivers/media/dvb-frontends/cx24123.h
+++ b/drivers/media/dvb-frontends/cx24123.h
@@ -21,6 +21,7 @@
 #ifndef CX24123_H
 #define CX24123_H
 
+#include <linux/kconfig.h>
 #include <linux/dvb/frontend.h>
 
 struct cx24123_config {
@@ -38,8 +39,7 @@
 	void (*agc_callback) (struct dvb_frontend *);
 };
 
-#if defined(CONFIG_DVB_CX24123) || (defined(CONFIG_DVB_CX24123_MODULE) \
-	&& defined(MODULE))
+#if IS_ENABLED(CONFIG_DVB_CX24123)
 extern struct dvb_frontend *cx24123_attach(const struct cx24123_config *config,
 					   struct i2c_adapter *i2c);
 extern struct i2c_adapter *cx24123_get_tuner_i2c_adapter(struct dvb_frontend *);