mmc: sdhci-of-at91: 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/mmc/host/sdhci-of-at91.ko | grep alias
$

After this patch:

$ modinfo drivers/mmc/host/sdhci-of-at91.ko | grep alias
alias:          of:N*T*Catmel,sama5d2-sdhciC*
alias:          of:N*T*Catmel,sama5d2-sdhci
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Acked-by: NLudovic Desroches <ludovic.desroches@atmel.com>
Acked-by: NAdrian Hunter <adrian.hunter@intel.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/sdhci-of-at91.c

@@ -100,6 +100,7 @@ static const struct of_device_id sdhci_at91_dt_match[] = {
 	{ .compatible = "atmel,sama5d2-sdhci", .data = &soc_data_sama5d2 },
 	{}
 };
+MODULE_DEVICE_TABLE(of, sdhci_at91_dt_match);
 
 #ifdef CONFIG_PM
 static int sdhci_at91_runtime_suspend(struct device *dev)