feat(ci): always pass -j to tfa make commands

There are a few ways to build tfa in CI, not all of which get a -j
argument. Pass it for consistency and speed when available.

Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
Change-Id: Id42088c2ba0ff85422cf466b431040ea12d77c57
diff --git a/script/build_package.sh b/script/build_package.sh
index 851d840..4342d5d 100755
--- a/script/build_package.sh
+++ b/script/build_package.sh
@@ -345,7 +345,7 @@
 		set +a
 	fi
 
-	make -C "$tf_root" $(cat "$tf_config_file") DEBUG="$DEBUG" BUILD_BASE=$tf_build_root V=1 "$@" \
+	make -C "$tf_root" $make_j_opts $(cat "$tf_config_file") DEBUG="$DEBUG" BUILD_BASE=$tf_build_root V=1 "$@" \
 		${fip_targets:-fip} &>>"$build_log" || fail_build
 	)
 }
@@ -368,7 +368,7 @@
 		set +a
 	fi
 
-	make -C "$tf_root" $(cat "$tf_config_file") DEBUG="$DEBUG" V=1 BUILD_BASE=$tf_build_root "$@" \
+	make -C "$tf_root" $make_j_opts $(cat "$tf_config_file") DEBUG="$DEBUG" V=1 BUILD_BASE=$tf_build_root "$@" \
 		${tf_extra_rules} &>>"$build_log" || fail_build
 	)
 }