The kernel hook scripts in /etc/kernel/postinst.d and /etc/kernel/prerm.d
were executed by the new-kernel-pkg --rpmposttrans and --remove options.
But with a BLS configuration the new-kernel-pkg script isn't executed and
instead the kernel-install plugins are used. Add a kernel-install plugin
that executes the hooks since packages like dkms and akmod make use of it.
Resolves: rhbz#1696202
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>