V4L/DVB (4934): Usbvision radio requires GainNormal at e register

Adds an option to select GainNormal at tda9887 and make usbvision
to use it.

Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
diff --git a/include/media/tuner.h b/include/media/tuner.h
index 3116e75..99acf84 100644
--- a/include/media/tuner.h
+++ b/include/media/tuner.h
@@ -145,6 +145,7 @@
 #define TDA9887_DEEMPHASIS_75 		(3<<16)
 #define TDA9887_AUTOMUTE 		(1<<18)
 #define TDA9887_GATING_18		(1<<19)
+#define TDA9887_GAIN_NORMAL		(1<<20)
 
 #ifdef __KERNEL__