mmc: sdhci: Check and call config_dll callback functions

Check if the low level driver supports config_dll callback function and
call it if it does. Call with dll disable before calling set_clock and
with dll enable after it.

Signed-off-by: Ashok Reddy Soma <ashok.reddy.soma@amd.com>
diff --git a/include/sdhci.h b/include/sdhci.h
index 24b4599..64a3d30 100644
--- a/include/sdhci.h
+++ b/include/sdhci.h
@@ -272,6 +272,8 @@
 	void	(*set_clock)(struct sdhci_host *host, u32 div);
 	int (*platform_execute_tuning)(struct mmc *host, u8 opcode);
 	int (*set_delay)(struct sdhci_host *host);
+	/* Callback function to set DLL clock configuration */
+	int (*config_dll)(struct sdhci_host *host, u32 clock, bool enable);
 	int	(*deferred_probe)(struct sdhci_host *host);
 
 	/**