configs: stm32mp1: only support SD card after NOR in bootcmd_stm32mp

In the boot command used in ST boards, bootcmd_stm32mp, only support
the SD card as second stage, where is found the bootfs with DISTRO.

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
diff --git a/include/configs/stm32mp1.h b/include/configs/stm32mp1.h
index f271b84..baaf2ff 100644
--- a/include/configs/stm32mp1.h
+++ b/include/configs/stm32mp1.h
@@ -123,7 +123,7 @@
  * for serial/usb: execute the stm32prog command
  * for mmc boot (eMMC, SD card), boot only on the same device
  * for nand or spi-nand boot, boot with on ubifs partition on UBI partition
- * for nor boot, use the default order
+ * for nor boot, use SD card = mmc0
  */
 #define STM32MP_BOOTCMD "bootcmd_stm32mp=" \
 	"echo \"Boot over ${boot_device}${boot_instance}!\";" \
@@ -136,6 +136,8 @@
 		"if test ${boot_device} = nand ||" \
 		  " test ${boot_device} = spi-nand ;" \
 		"then env set boot_targets ubifs0; fi;" \
+		"if test ${boot_device} = nor;" \
+		"then env set boot_targets mmc0; fi;" \
 		"run distro_bootcmd;" \
 	"fi;\0"