copr: provision - install ethtool again

This one is fedora-copr-only hack, and as such the ethtool package
isn't supposed to be put as Requires: into copr-builder.  To not
C&P between x86_64/ppc64le playbooks, put the ethtool hack into
separate tasks file.

roles/copr/backend/files/provision/builderpb_nova.yml

@@ -50,5 +50,4 @@
   tasks:
   - include: "provision_builder_tasks.yml"
 
-  - name: disable offloading
-    command: ethtool -K eth0 tso off gro off gso off
+  - include: "offloading_hack.yml"

roles/copr/backend/files/provision/builderpb_nova_ppc64le.yml

@@ -50,5 +50,4 @@
   tasks:
   - include: "provision_builder_tasks.yml"
 
-  - name: disable offloading
-    command: ethtool -K eth0 tso off gro off gso off
+  - include: "offloading_hack.yml"

roles/copr/backend/files/provision/offloading_hack.yml

@@ -0,0 +1,9 @@
+# TODO: is this still needed?
+# https://bugzilla.redhat.com/show_bug.cgi?id=1268192
+
+- name: install ethtool
+  package: state=present name=ethtool
+  when: prepare_base_image
+
+- name: disable offloading
+  command: ethtool -K eth0 tso off gro off gso off