crypto: picoxcell - add connection ID to the clock name

For using the device tree probing we use a connection ID for the
clk_get() operation.

Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/drivers/crypto/picoxcell_crypto.c b/drivers/crypto/picoxcell_crypto.c
index 4ffb903..d119e0e 100644
--- a/drivers/crypto/picoxcell_crypto.c
+++ b/drivers/crypto/picoxcell_crypto.c
@@ -1724,7 +1724,7 @@
 
 	spin_lock_init(&engine->hw_lock);
 
-	engine->clk = clk_get(&pdev->dev, NULL);
+	engine->clk = clk_get(&pdev->dev, "ref");
 	if (IS_ERR(engine->clk)) {
 		dev_info(&pdev->dev, "clk unavailable\n");
 		device_remove_file(&pdev->dev, &dev_attr_stat_irq_thresh);