board: am335x/mux: configure the pins for 8-bit data transfer on MMC1

This is required for proper operation of the 8-bit data transfers.
This fixes transient errors seen on BeagleBone Black.

Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
diff --git a/board/ti/am335x/mux.c b/board/ti/am335x/mux.c
index 37a5997..6e1ede3 100644
--- a/board/ti/am335x/mux.c
+++ b/board/ti/am335x/mux.c
@@ -93,6 +93,10 @@
 };
 
 static struct module_pin_mux mmc1_pin_mux[] = {
+	{OFFSET(gpmc_ad7), (MODE(1) | RXACTIVE | PULLUP_EN)},	/* MMC1_DAT7 */
+	{OFFSET(gpmc_ad6), (MODE(1) | RXACTIVE | PULLUP_EN)},	/* MMC1_DAT6 */
+	{OFFSET(gpmc_ad5), (MODE(1) | RXACTIVE | PULLUP_EN)},	/* MMC1_DAT5 */
+	{OFFSET(gpmc_ad4), (MODE(1) | RXACTIVE | PULLUP_EN)},	/* MMC1_DAT4 */
 	{OFFSET(gpmc_ad3), (MODE(1) | RXACTIVE | PULLUP_EN)},	/* MMC1_DAT3 */
 	{OFFSET(gpmc_ad2), (MODE(1) | RXACTIVE | PULLUP_EN)},	/* MMC1_DAT2 */
 	{OFFSET(gpmc_ad1), (MODE(1) | RXACTIVE | PULLUP_EN)},	/* MMC1_DAT1 */