u-boot:scripts: improve handling of dt overlays

- don't attempt to load devicetree overlays when
  loading the device tree failed
- added missing call to fdt addr, which is required
  for all following fdt commands to work

recipes-bsp/bootscript/bootscript-uboot/boot.scr.cfg

@@ -14,23 +14,23 @@ if fatload mmc ${current_partition} ${loadaddr} boot.cfg  && env import -t ${loa
     if test -n ${devicetree};then
         echo "Loading devicetree ${devicetree} ..."
         if fatload mmc ${current_partition} ${fdt_addr} ${devicetree}; then
-            true
+            fdt addr ${fdt_addr}
+
+            if test -n ${overlays}; then
+                for ov in ${overlays}; do
+                    echo "Overlaying ${ov} ..."
+                    if fatload mmc ${current_partition} ${loadaddr} ${ov}; then
+                        fdt resize ${filesize} && fdt apply ${loadaddr}
+                    else
+                        echo "Failed to load overlay ${ov}"
+                    fi
+                done
+            fi
         else
             echo "Failed to load devicetree ${devicetree}"
         fi
     fi
 
-    if test -n ${overlays}; then
-        for ov in ${overlays}; do
-            echo "Overlaying ${ov} ..."
-            if fatload mmc ${current_partition} ${loadaddr} ${ov}; then
-                fdt resize ${filesize} && fdt apply ${loadaddr}
-            else
-                echo "Failed to load overlay ${ov}"
-            fi
-        done
-    fi
-
     initrd=-
     if test -n ${initramfs}; then
         echo "Loading initramfs ${initramfs} ..."