buffet: Move privet options and state into buffet

Now it's a single binary and don't deserve separate configs and states.

BUG=brillo:1211,brillo:1212
CQ-DEPEND=CL:281024
TEST=`FEATURES=test emerge-gizmo buffet`

Change-Id: I5886d3092b8ccba57be5f2f6edf7ddbc36fd199b
Reviewed-on: https://chromium-review.googlesource.com/281018
Reviewed-by: Vitaly Buka <vitalybuka@chromium.org>
Tested-by: Vitaly Buka <vitalybuka@chromium.org>
Commit-Queue: Vitaly Buka <vitalybuka@chromium.org>
diff --git a/buffet/device_registration_info.h b/buffet/device_registration_info.h
index 85b4b65..860a8fc 100644
--- a/buffet/device_registration_info.h
+++ b/buffet/device_registration_info.h
@@ -147,7 +147,9 @@
                            const std::string& service_url,
                            chromeos::ErrorPtr* error);
 
+  // TODO(vitalybuka): remove getters and pass config to dependent code.
   const BuffetConfig& GetConfig() const { return *config_; }
+  BuffetConfig* GetMutableConfig() { return config_.get(); }
 
   base::WeakPtr<DeviceRegistrationInfo> AsWeakPtr() {
     return weak_factory_.GetWeakPtr();