mmc: mmci: add validate_data callback

This patch adds validate_data callback at mmci_host_ops
to check specific constraints of variant.
Move mmci_validate_data function to regroup mmci_host_ops interfaces.

Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h
index bcf3e8b..ed59baf 100644
--- a/drivers/mmc/host/mmci.h
+++ b/drivers/mmc/host/mmci.h
@@ -273,6 +273,7 @@
 
 /* mmci variant callbacks */
 struct mmci_host_ops {
+	int (*validate_data)(struct mmci_host *host, struct mmc_data *data);
 	int (*prep_data)(struct mmci_host *host, struct mmc_data *data,
 			 bool next);
 	void (*unprep_data)(struct mmci_host *host, struct mmc_data *data,