bootscript:dt: Added devicetree description file for i.MX8

Added an description file with the default devicetree for i.MX8
devices.
The file is parsed/used by the post-install scripts to generate
the boot configuration.

BCS 746-000877

recipes-bsp/bootscript/bootscript.bb

-SUMMARY = "Garz & Fricke platform bootscript for FNGBoot"
-HOMEPAGE = "https://garz-fricke.com"
+SUMMARY = "SECO Northern Europe platform bootscript"
+HOMEPAGE = "https://north.seco.com"
 
 LICENSE = "Apache-2.0"
 LIC_FILES_CHKSUM = "file://${COMMON_LICENSE_DIR}/Apache-2.0;md5=89aea4e17d99a7cacdbeed46a0096b10"
 
 inherit deploy
 
-RPROVIDES_${PN} += " boot.cfg  "
-PROVIDES += " boot.cfg  "
+RPROVIDES_${PN} += " boot.cfg "
+PROVIDES += " boot.cfg "
 
-SRC_URI = "\
+RPROVIDES_${PN}_append_mx8 = " devicetree "
+PROVIDES_append_mx8 = " devicetree "
+
+SRC_URI = " \
     file://boot.cfg \
 "
 
@@ -20,8 +23,13 @@ do_configure() {
 }
 
 do_install() {
-	install -d ${D}/boot
+    install -d ${D}/boot
     install -m 0644 ${S}/boot.cfg ${D}/boot/boot.cfg
 }
 
-FILES_${PN} = "boot/boot.cfg"
+do_install_append_mx8() {
+    echo ${DEFAULT_DEVICETREE} >> ${D}/boot/devicetree
+}
+
+FILES_${PN} = " boot/boot.cfg "
+FILES_${PN}_append_mx8 = " boot/devicetree "