net: dsa: bcm_sf2: Fix module autoload for OF registration

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/net/dsa/bcm_sf2.ko | grep alias
alias:          platform:brcm-sf2

After this patch:

$ modinfo drivers/net/dsa/bcm_sf2.ko | grep alias
alias:          platform:brcm-sf2
alias:          of:N*T*Cbrcm,bcm7445-switch-v4.0C*
alias:          of:N*T*Cbrcm,bcm7445-switch-v4.0

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/bcm_sf2.c

@@ -1158,6 +1158,7 @@ static const struct of_device_id bcm_sf2_of_match[] = {
 	{ .compatible = "brcm,bcm7445-switch-v4.0" },
 	{ /* sentinel */ },
 };
+MODULE_DEVICE_TABLE(of, bcm_sf2_of_match);
 
 static struct platform_driver bcm_sf2_driver = {
 	.probe	= bcm_sf2_sw_probe,