sm6225-common: Import `hardware/xiaomi` namespace

Change-Id: I9aca52286bcf8dd2efad42245dfff36cda02c24e
diff --git a/Android.bp b/Android.bp
index cdaa513..61162c9 100644
--- a/Android.bp
+++ b/Android.bp
@@ -5,4 +5,7 @@
 //
 
 soong_namespace {
+    imports: [
+        "hardware/xiaomi",
+    ],
 }