Apply the cpu count hardware check in our base job

The motivation for this is some hypervisors in rackspace boot with a
single cpu core usable and that impacts jobs that expect more. The
previous change that adds this update to base-test covers the background
in a lot more detail.

Now that we've applied this to base-test and it works we can apply it to
the base job. We don't apply it to base-minimal as that base jobs is
extremely minimal and adding extra checks to it seems the opposite of
what we intend.

Change-Id: I01b827ff8fda4c0a81e536c70d7417995ff23aa9

playbooks/base/pre.yaml

@@ -34,6 +34,9 @@
   hosts: all
   roles:
     - validate-host
+    # Hardware-check runs after validate-host as validate-host gathers host
+    # facts which are used to check the hardware.
+    - hardware-check
     - prepare-workspace-git
     - mirror-info
     - role: configure-mirrors