mmc: mmci: add dma_start callback

This patch adds dma_start callback to mmci_host_ops.
Create a generic mmci_dma_start function which regroup
common action between variant.

Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/mmci_qcom_dml.c

@@ -189,6 +189,7 @@ static struct mmci_host_ops qcom_variant_ops = {
 	.get_next_data = mmci_dmae_get_next_data,
 	.dma_setup = qcom_dma_setup,
 	.dma_release = mmci_dmae_release,
+	.dma_start = mmci_dmae_start,
 };
 
 void qcom_variant_init(struct mmci_host *host)