atmel-mci: Add missing flush_dcache_page() in PIO transfer code

Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c
index 02529af..7a3f243 100644
--- a/drivers/mmc/host/atmel-mci.c
+++ b/drivers/mmc/host/atmel-mci.c
@@ -1253,6 +1253,7 @@
 			nbytes += 4;
 
 			if (offset == sg->length) {
+				flush_dcache_page(sg_page(sg));
 				host->sg = sg = sg_next(sg);
 				if (!sg)
 					goto done;