mmc: arm_pl180_mmci: Add missing clk_free

Add missing clk_free() call in case of failure
when enabling the clock.

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

drivers/mmc/arm_pl180_mmci.c

@@ -430,6 +430,7 @@ static int arm_pl180_mmc_probe(struct udevice *dev)
 
 	ret = clk_enable(&clk);
 	if (ret) {
+		clk_free(&clk);
 		dev_err(dev, "failed to enable clock\n");
 		return ret;
 	}