Add dirgroup for trusty genrule

Bug: 358302178
Test: m lk.elf.x86_64 lk.elf.arm64
Change-Id: Ic3e41c6a38aaa9dd87dbc4a0215c02d19b3063a0
diff --git a/Android.bp b/Android.bp
new file mode 100644
index 0000000..c77a803
--- /dev/null
+++ b/Android.bp
@@ -0,0 +1,5 @@
+dirgroup {
+    name: "trusty_dirgroup_system_core",
+    dirs: ["."],
+    visibility: ["//trusty/vendor/google/aosp/scripts"],
+}