[ARM] amba drivers: don't pass a consumer clock name for devices with unique clocks

Where devices only have one consumer, passing a consumer clock ID
has no real benefit, and it only encourages wrong implementations of
the clk API.  Remove it.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

drivers/mmc/host/mmci.c

@@ -500,7 +500,7 @@ static int mmci_probe(struct amba_device *dev, void *id)
 	}
 
 	host = mmc_priv(mmc);
-	host->clk = clk_get(&dev->dev, "MCLK");
+	host->clk = clk_get(&dev->dev, NULL);
 	if (IS_ERR(host->clk)) {
 		ret = PTR_ERR(host->clk);
 		host->clk = NULL;