mmc: dw_mmc: fix fifo access for 64-bit

mci_writew causes a failure of fifo access for 64-bit.
mci_writeq is correct.

Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
Acked-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index a443820..753c55c 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -1373,8 +1373,9 @@
 		int len = dw_mci_push_part_bytes(host, buf, cnt);
 		buf += len;
 		cnt -= len;
+
 		if (host->part_buf_count == 8) {
-			mci_writew(host, DATA(host->data_offset),
+			mci_writeq(host, DATA(host->data_offset),
 					host->part_buf);
 			host->part_buf_count = 0;
 		}