mmc: atmel_sdhci: Add sam9x60-sdhci compatibility string

Add new compatibility string for matching sam9x60 product.

Signed-off-by: Sandeep Sheriker Mallikarjun <sandeepsheriker.mallikarjun@microchip.com>
diff --git a/drivers/mmc/atmel_sdhci.c b/drivers/mmc/atmel_sdhci.c
index d930ed8..2b797c9 100644
--- a/drivers/mmc/atmel_sdhci.c
+++ b/drivers/mmc/atmel_sdhci.c
@@ -112,6 +112,7 @@
 
 static const struct udevice_id atmel_sdhci_ids[] = {
 	{ .compatible = "atmel,sama5d2-sdhci" },
+	{ .compatible = "microchip,sam9x60-sdhci" },
 	{ }
 };