V4L/DVB (9657): em28xx: add a functio to write on a single register

Introduce a new function that writes to a single register.  This is
useful because the vast majority of register writes are a single
register, and this format permits or'ing register value bits together.

Signed-off-by: Devin Heitmueller <devin.heitmueller@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/em28xx/em28xx.h b/drivers/media/video/em28xx/em28xx.h
index 6d04ebf..4fde52b 100644
--- a/drivers/media/video/em28xx/em28xx.h
+++ b/drivers/media/video/em28xx/em28xx.h
@@ -555,6 +555,8 @@
 int em28xx_write_regs_req(struct em28xx *dev, u8 req, u16 reg, char *buf,
 			  int len);
 int em28xx_write_regs(struct em28xx *dev, u16 reg, char *buf, int len);
+int em28xx_write_reg(struct em28xx *dev, u16 reg, u8 val);
+
 int em28xx_audio_analog_set(struct em28xx *dev);
 int em28xx_audio_setup(struct em28xx *dev);