Revert "refactor: remove unused model parameters"

This reverts commit a318f9dff661046cd3ad9d4cc21ed326d54a545d.

Signed-off-by: Maksims Svecovs <maksims.svecovs@arm.com>
Change-Id: I0a909c9ce9453c8cafd578579679985abbf3135c
diff --git a/model/css-rdn1edge.sh b/model/css-rdn1edge.sh
index f68b422..c9084c0 100644
--- a/model/css-rdn1edge.sh
+++ b/model/css-rdn1edge.sh
@@ -9,6 +9,7 @@
 
 cat <<EOF >"$model_param_file"
 -C board.flashloader0.fname=$fip_bin
+-C board.virtioblockdevice.image_path=$busybox_bin
 -C css.cmn600.force_rnsam_internal=false
 -C css.cmn600.mesh_config_file=RD_N1_E1_cmn600.yml
 -C css.gic_distributor.ITS-device-bits=20