[media] st-cec: Fix module autoload

If the driver is built as a module, autoload won't work because the module
alias information is not filled. So user-space can't match the registered
device with the corresponding module.

Export the module alias information using the MODULE_DEVICE_TABLE() macro.

Before this patch:

$ modinfo drivers/staging/media//st-cec/stih-cec.ko | grep alias
$

After this patch:

$ modinfo drivers/staging/media//st-cec/stih-cec.ko | grep alias
alias:          of:N*T*Cst,stih-cecC*
alias:          of:N*T*Cst,stih-cec
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Acked-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/staging/media/st-cec/stih-cec.c

@@ -362,6 +362,7 @@ static const struct of_device_id stih_cec_match[] = {
 	},
 	{},
 };
+MODULE_DEVICE_TABLE(of, stih_cec_match);
 
 static struct platform_driver stih_cec_pdrv = {
 	.probe	= stih_cec_probe,