V4L/DVB (7479): proper prototype for zoran_device.c:zr36016_write()

This patch adds a proper prototype for zr36016_write() in
drivers/media/video/zoran_card.h

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>