power: reset: at91-poweroff: 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/power/reset/at91-poweroff.ko | grep alias
$

After this patch:

$ modinfo drivers/power/reset/at91-poweroff.ko | grep alias
alias:          of:N*T*Catmel,at91sam9x5-shdwcC*
alias:          of:N*T*Catmel,at91sam9x5-shdwc
alias:          of:N*T*Catmel,at91sam9rl-shdwcC*
alias:          of:N*T*Catmel,at91sam9rl-shdwc
alias:          of:N*T*Catmel,at91sam9260-shdwcC*
alias:          of:N*T*Catmel,at91sam9260-shdwc

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>

drivers/power/reset/at91-poweroff.c

@@ -169,6 +169,7 @@ static const struct of_device_id at91_poweroff_of_match[] = {
 	{ .compatible = "atmel,at91sam9x5-shdwc", },
 	{ /*sentinel*/ }
 };
+MODULE_DEVICE_TABLE(of, at91_poweroff_of_match);
 
 static struct platform_driver at91_poweroff_driver = {
 	.remove = __exit_p(at91_poweroff_remove),