fix(ci): also clone submodules when cloning to apply a patch

The repository will be cloned when applying a patch locally to keep the
main tree clean. However, the modules must also be explicitly pulled in.

Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
Change-Id: I4d5d9c809ec420b1d8b7c96b88a97c93593140b2
diff --git a/script/build_package.sh b/script/build_package.sh
index cbe1b02..f9fbebe 100755
--- a/script/build_package.sh
+++ b/script/build_package.sh
@@ -1082,7 +1082,7 @@
 		popd
 
 		# git will hard link when cloning locally, no need for --depth=1
-		git clone "$tf_root" $root --shallow-submodules
+		git clone "$tf_root" $root --shallow-submodules --recurse-submodules
 
 		tf_root=$root # next apply_tf_patch will run in the same hook
 		set_hook_var "tf_root" "$root" # for anyone outside the hook