imx6ul: opos6ul: in Serial Downloader boot mode use ymodem

When booting in Serial Downloader mode load the U-Boot image using
ymodem.

Signed-off-by: Sébastien Szymanski <sebastien.szymanski@armadeus.com>

arch/arm/mach-imx/mx6/opos6ul.c

@@ -208,6 +208,16 @@ static struct mx6_ddr3_cfg mem_ddr = {
 	.trasmin = 3750,
 };
 
+void board_boot_order(u32 *spl_boot_list)
+{
+	unsigned int bmode = readl(&src_base->sbmr2);
+
+	if (((bmode >> 24) & 0x03) == 0x01) /* Serial Downloader */
+		spl_boot_list[0] = BOOT_DEVICE_UART;
+	else
+		spl_boot_list[0] = spl_boot_device();
+}
+
 static void ccgr_init(void)
 {
 	struct mxc_ccm_reg *ccm = (struct mxc_ccm_reg *)CCM_BASE_ADDR;