mmc: mmci: add get_datactrl_cfg callback and helper functions

This patch adds get_datactrl_cfg callback in mmci_host_ops
to allow to get datactrl configuration specific at variant.
Common helper function is defined and could be call by variant.
Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/mmci.h

@@ -362,6 +362,7 @@ struct mmci_host_ops {
 			 bool next);
 	void (*unprep_data)(struct mmci_host *host, struct mmc_data *data,
 			    int err);
+	u32 (*get_datactrl_cfg)(struct mmci_host *host);
 	void (*get_next_data)(struct mmci_host *host, struct mmc_data *data);
 	int (*dma_setup)(struct mmci_host *host);
 	void (*dma_release)(struct mmci_host *host);
@@ -429,6 +430,11 @@ struct mmci_host {
 void mmci_write_clkreg(struct mmci_host *host, u32 clk);
 void mmci_write_pwrreg(struct mmci_host *host, u32 pwr);
 
+static inline u32 mmci_dctrl_blksz(struct mmci_host *host)
+{
+	return (ffs(host->data->blksz) - 1) << 4;
+}
+
 #ifdef CONFIG_DMA_ENGINE
 int mmci_dmae_prep_data(struct mmci_host *host, struct mmc_data *data,
 			bool next);