spi/bcm63xx-hsspi: check result of clk_prepare_enable

Ensure we notice if the clock cannot be enabled for any reason and pass
the error down.

Signed-off-by: Jonas Gorski <[e-mail]>
Signed-off-by: Mark Brown <[e-mail]>

drivers/spi/spi-bcm63xx-hsspi.c

···
 	if (!rate)
 		return -EINVAL;
 
-	clk_prepare_enable(clk);
+	ret = clk_prepare_enable(clk);
+	if (ret)
+		return ret;
 
 	master = spi_alloc_master(&pdev->dev, sizeof(*bs));
 	if (!master) {