[r=cjwatson] Install grub in ppc64el cloud images so they are bootable (LP: #1538610)

debian/changelog

@@ -1,3 +1,9 @@
+livecd-rootfs (2.372) UNRELEASED; urgency=medium
+
+  * Install grub in ppc64el cloud images so they are bootable (LP: #1538610)
+
+ -- Daniel Watkins <daniel.watkins@canonical.com>  Wed, 27 Jan 2016 15:47:39 +0000
+
 livecd-rootfs (2.371) xenial; urgency=medium
 
   * Remove unneeded packages from the root.tar.{gz,xz} cloud image targets

live-build/ubuntu-cpc/hooks/034-disk-image-ppc64el.binary

@@ -40,6 +40,11 @@ EOF
         --boot-directory=/boot \
         --target=powerpc-ieee1275
 
+    chroot mountpoint dpkg-divert --local --rename /etc/grub.d/30_os-prober
+    chroot mountpoint update-grub
+    sed -i "s,root=.* ,root=LABEL=cloudimg-rootfs ,g" mountpoint/boot/grub/grub.cfg
+    chroot mountpoint dpkg-divert --remove --local --rename /etc/grub.d/30_os-prober
+
     umount_partition mountpoint
     rmdir mountpoint
 }