[pci] Move drivers for test out of /system

This fixes issues with |core| builds and makes it
consistent with |bringup| builds.

ZX-3146 #comment

Change-Id: Iec05c37c117c9236955579025fd70709d57c0fc6
diff --git a/zircon/system/dev/bus/pci/BUILD.gn b/zircon/system/dev/bus/pci/BUILD.gn
index 5521c45..ed66b47 100644
--- a/zircon/system/dev/bus/pci/BUILD.gn
+++ b/zircon/system/dev/bus/pci/BUILD.gn
@@ -8,6 +8,9 @@
   deps = [
     ":bus-pci",
     ":bus-pci.proxy",
+    ":pci_fake",
+    ":pci_fake.proxy",
+    ":pci_protocol_test_driver",
   ]
 }
 
@@ -128,9 +131,6 @@
     "test/driver/driver_tests.cpp",
   ]
   deps = [
-    ":pci_fake",
-    ":pci_fake.proxy",
-    ":pci_protocol_test_driver",
     "$zx/system/fidl/fuchsia-device-test:c",
     "$zx/system/ulib/ddk",
     "$zx/system/ulib/ddktl",