mmc: sdhci-pltfm: Constify the ops field of sdhci_pltfm_data struct

All users of the sdhci_ops struct in the sdhci core already treat it as
const.  The sdhci-pltfm code itself never actually looks at the ops field
of the sdhci_pltfm_data struct and merely passes it on to the sdhci core,
so make we can make it const in the sdhci_pltfm_data struct as well.
This allows us to declare sdhci_ops structs as const in drivers using
the sdhci-pltfm helper code.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/host/sdhci-pltfm.h

@@ -16,7 +16,7 @@
 #include "sdhci.h"
 
 struct sdhci_pltfm_data {
-	struct sdhci_ops *ops;
+	const struct sdhci_ops *ops;
 	unsigned int quirks;
 };