build.sh: add bitbake device-tree exception handling

Signed-off-by: Teoh Ji Sheng <ji.sheng.teoh@intel.com>

build.sh

@@ -192,8 +192,10 @@ bitbake_image() {
 		bitbake u-boot-socfpga -c cleanall
 		echo -e "\n[INFO] Clean up previous ghrd build if any"
 		bitbake hw-ref-design -c cleanall
-		echo -e "\n[INFO] Clean up previous dtb build if any"
-		bitbake device-tree -c cleanall
+		if [[ "$MACHINE" == *"agilex"* || "$MACHINE" == "stratix10" ]]; then
+			echo -e "\n[INFO] Clean up previous dtb build if any"
+			bitbake device-tree -c cleanall
+		fi
 
 		echo -e "\n[INFO] Start bitbake process for target config.."
 		bitbake console-image-minimal gsrd-console-image 2>&1