kernel.spec kernel-install integration

[Harald Hoyer]

Hi Josh,

as mentioned on IRC, here is the patch for the rawhide kernel.spec.

This patch is part of an upstream coordination, intended to unify the various
ways distributions handle:

- installation of kernels in the system
- create the matching initrds; hooking up the various implementations of
  initramfs generators into the kernel package installation process
- optionally/automatically create bootable rescue images to be able to recover
  from failures:
  https://fedoraproject.org/wiki/Features/DracutHostOnly

All the above functionality is provided by the “kernel-install” tool:
http://www.freedesktop.org/software/systemd/man/kernel-install.html

It features:
- flexible hookup/plugin directories to manage kernel installation and
  uninstallation. initrd, bootloader, rescue image management, all plug into
  that facility.

- strict separation of distribution-supplied logic and local customization
  logic; system administrators are able to overwrite and replace/extend any part
  of the default logic if needed

- hide distribution-specific logic behind a standardized command line interface

- unify the custom kernel installation from the source tree with the usual
  kernel package installation; like the current /sbin/installkernel