fix: prevent `jq` from adding newlines to FVP parameters

Removes the `--slurp` and `--ascii-output` options.

Change-Id: I9367d6ba38a7e2f4388d91f71194a682583a8c39
Signed-off-by: Chris Kay <chris.kay@arm.com>
diff --git a/fvp_utils.sh b/fvp_utils.sh
index af050c4..1529ce0 100644
--- a/fvp_utils.sh
+++ b/fvp_utils.sh
@@ -634,7 +634,7 @@
     # include the model parameters
     while read -r line; do
         if [ -n "$line" ]; then
-            yaml_line="- $(echo "${line}" | jq -Rsa .)"
+            yaml_line="- $(echo "${line}" | jq -R .)"
             sed -i -e "/{BOOT_ARGUMENTS}/i \ \ \ \ $yaml_line" "$yaml_file"
         fi
     done < "$lava_model_params"