media: davinci: vpbe_osd: mark read reg function as __always_unused

Such function is currently unused, but could be needed in the
future. So, keep it, marking it as __always_unused, in order to
avoid a clang W=1 error.
Reviewed-by: Lad Prabhakar <prabhakar.csengg@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/platform/davinci/vpbe_osd.c

@@ -45,7 +45,7 @@ static const struct platform_device_id vpbe_osd_devtype[] = {
 MODULE_DEVICE_TABLE(platform, vpbe_osd_devtype);
 
 /* register access routines */
-static inline u32 osd_read(struct osd_state *sd, u32 offset)
+static inline u32 __always_unused osd_read(struct osd_state *sd, u32 offset)
 {
 	struct osd_state *osd = sd;