[kernel][arm64] Add some missing deps to usercopy

Added some missing deps used by user_copy.cc on
arm64.

No functional changes.

Test: fx build
Change-Id: I16e1096141425d76cc275038ba61eed0fc2abab7
Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/693283
Reviewed-by: Joshua Seaton <joshuaseaton@google.com>
Commit-Queue: Gianfranco Valentino <gevalentino@google.com>
diff --git a/zircon/kernel/arch/arm64/user-copy/BUILD.gn b/zircon/kernel/arch/arm64/user-copy/BUILD.gn
index 670029c..ba3ff55 100644
--- a/zircon/kernel/arch/arm64/user-copy/BUILD.gn
+++ b/zircon/kernel/arch/arm64/user-copy/BUILD.gn
@@ -1,4 +1,4 @@
-# Copyright 2021 The Fuchsia Authors
+# Copyright 2022 The Fuchsia Authors
 #
 # Use of this source code is governed by a MIT-style
 # license that can be found in the LICENSE file or at
@@ -9,5 +9,9 @@
     "user-copy.S",
     "user-copy.cc",
   ]
-  deps = [ "//zircon/kernel/lib/user_copy" ]
+  deps = [
+    "//zircon/kernel/lib/arch",
+    "//zircon/kernel/lib/libc",
+    "//zircon/kernel/lib/user_copy",
+  ]
 }