RAUC: turn this into a configurable target

I am not using the generic rootfs target because it is optimized for
using fakeroot, and because it extracts that tarball from rootfs-common.
Rather than fighting the hooks (ROOTFS_XXX_POST_GEN_HOOKS is the only
thing which runs outside of fakeroot) and doing extra work by unpacking,
let's go all the way down to raw Makefile.

Change-Id: I075204291fbeac8d1af97a0a7c1254054ef1f594
diff --git a/configs/czechlight_clearfog_defconfig b/configs/czechlight_clearfog_defconfig
index bbe9ae7..dcd39c3 100644
--- a/configs/czechlight_clearfog_defconfig
+++ b/configs/czechlight_clearfog_defconfig
@@ -13,7 +13,7 @@
 # BR2_TARGET_GENERIC_REMOUNT_ROOTFS_RW is not set
 BR2_ROOTFS_OVERLAY="$(BR2_EXTERNAL_CZECHLIGHT_PATH)/board/czechlight/common/overlay/ $(BR2_EXTERNAL_CZECHLIGHT_PATH)/board/czechlight/clearfog/overlay/"
 BR2_ROOTFS_POST_BUILD_SCRIPT="$(BR2_EXTERNAL_CZECHLIGHT_PATH)/board/czechlight/common/install-rauc-cert.sh $(BR2_EXTERNAL_CZECHLIGHT_PATH)/board/czechlight/clearfog/copy-boot-scr.sh"
-BR2_ROOTFS_POST_IMAGE_SCRIPT="support/scripts/genimage.sh $(BR2_EXTERNAL_CZECHLIGHT_PATH)/board/czechlight/clearfog/mk-rauc-bundle.sh ${BR2_EXTERNAL_CZECHLIGHT_PATH}/board/czechlight/clearfog/usb-flash-genimage.sh"
+BR2_ROOTFS_POST_IMAGE_SCRIPT="support/scripts/genimage.sh ${BR2_EXTERNAL_CZECHLIGHT_PATH}/board/czechlight/clearfog/usb-flash-genimage.sh"
 BR2_ROOTFS_POST_SCRIPT_ARGS="-c $(BR2_EXTERNAL_CZECHLIGHT_PATH)/board/czechlight/clearfog/genimage.cfg"
 BR2_LINUX_KERNEL=y
 BR2_LINUX_KERNEL_CUSTOM_VERSION=y
@@ -67,7 +67,7 @@
 BR2_PACKAGE_HOST_DOSFSTOOLS=y
 BR2_PACKAGE_HOST_GENIMAGE=y
 BR2_PACKAGE_HOST_MTOOLS=y
-BR2_PACKAGE_HOST_RAUC=y
-BR2_PACKAGE_CZECHLIGHT_CFG_FS=y
 CZECHLIGHT_CFG_FS_SIZE="256M"
+CZECHLIGHT_RAUC_ROOTFS=y
+CZECHLIGHT_RAUC_COMPATIBLE="czechlight-clearfog"
 CZECHLIGHT_NETCONF=y