mmc: dw_mmc: Regression fix for non-IDMAC DMA

3ec7699d3bb1b0ee7 ("mmc: dw_mmc: Add support for pre_req and post_req")
broke non-IDMAC DMA, because dw_mci_pre_dma_transfer() is valid only if
using internal DMA. In case of using other DMA it returns -ENOSYS. It
prevents the DMA operations.  This patch makes dw_mci_pre_dma_transfer()
effective in all DMA cases again.

Reported-by: James Hogan <james@albanarts.com>
Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
Reviewed-by: Namjae Jeon <linkinjeon@gmail.com>
Acked-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/host/dw_mmc.c

@@ -429,6 +429,15 @@ static int dw_mci_idmac_init(struct dw_mci *host)
 	return 0;
 }
 
+static struct dw_mci_dma_ops dw_mci_idmac_ops = {
+	.init = dw_mci_idmac_init,
+	.start = dw_mci_idmac_start_dma,
+	.stop = dw_mci_idmac_stop_dma,
+	.complete = dw_mci_idmac_complete_dma,
+	.cleanup = dw_mci_dma_cleanup,
+};
+#endif /* CONFIG_MMC_DW_IDMAC */
+
 static int dw_mci_pre_dma_transfer(struct dw_mci *host,
 				   struct mmc_data *data,
 				   bool next)
@@ -468,22 +477,6 @@ static int dw_mci_pre_dma_transfer(struct dw_mci *host,
 	return sg_len;
 }
 
-static struct dw_mci_dma_ops dw_mci_idmac_ops = {
-	.init = dw_mci_idmac_init,
-	.start = dw_mci_idmac_start_dma,
-	.stop = dw_mci_idmac_stop_dma,
-	.complete = dw_mci_idmac_complete_dma,
-	.cleanup = dw_mci_dma_cleanup,
-};
-#else
-static int dw_mci_pre_dma_transfer(struct dw_mci *host,
-				   struct mmc_data *data,
-				   bool next)
-{
-	return -ENOSYS;
-}
-#endif /* CONFIG_MMC_DW_IDMAC */
-
 static void dw_mci_pre_req(struct mmc_host *mmc,
 			   struct mmc_request *mrq,
 			   bool is_first_req)