pw_system: Add missing config dependency in Bazel

This is also harmonizing with GN build.

Change-Id: I9acece48ace085c8067a12e061a9075b435bf146
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/261692
Docs-Not-Needed: Armando Montanez <amontanez@google.com>
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>
Reviewed-by: Ted Pudlik <tpudlik@google.com>
Commit-Queue: Auto-Submit <auto-submit@pigweed-service-accounts.iam.gserviceaccount.com>
Docs-Not-Needed: Ronan Chauvin <ronanchauvin@gmail.com>
Reviewed-by: Armando Montanez <amontanez@google.com>
Pigweed-Auto-Submit: Ted Pudlik <tpudlik@google.com>
Pigweed-Auto-Submit: Armando Montanez <amontanez@google.com>

pw_system/BUILD.bazel

@@ -155,6 +155,7 @@ pw_facade(
     backend = ":rpc_server_backend",
     strip_include_prefix = "public",
     deps = [
+        ":config",
         "//pw_thread:thread_core",
     ],
 )