chromeos_config: remove x86-generic-*

Remove all x86-generic-* boards.

BUG=chromium:729645
TEST=chromeos_config_unittest

Change-Id: I83bf8130a4571113126a48156a805ab15c01aacf
Reviewed-on: https://chromium-review.googlesource.com/588081
Commit-Ready: Paul Hobbs <phobbs@google.com>
Tested-by: Paul Hobbs <phobbs@google.com>
Reviewed-by: Paul Hobbs <phobbs@google.com>
diff --git a/scripts/cbuildbot_unittest.py b/scripts/cbuildbot_unittest.py
index 1fd2842..f540add 100644
--- a/scripts/cbuildbot_unittest.py
+++ b/scripts/cbuildbot_unittest.py
@@ -21,7 +21,7 @@
   def testIsDistributedBuilder(self):
     """Tests for _IsDistributedBuilder() under various configurations."""
     parser = cbuildbot._CreateParser()
-    argv = ['x86-generic-paladin']
+    argv = ['amd64-generic-paladin']
     (options, _) = cbuildbot.ParseCommandLine(parser, argv)
     options.buildbot = False