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 <jogo@openwrt.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
diff --git a/drivers/spi/spi-bcm63xx-hsspi.c b/drivers/spi/spi-bcm63xx-hsspi.c
index 6a763a8..949dfb5 100644
--- a/drivers/spi/spi-bcm63xx-hsspi.c
+++ b/drivers/spi/spi-bcm63xx-hsspi.c
@@ -351,7 +351,9 @@
 	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) {