Patch for kernel variants/flavors

Here is a patch for the kernel.spec, which changes the version of kernel flavor/variants to end in "-$flavor" instead of ".$flavor". This change makes it easier to detect a flavor and a parser can separate it from the architecture. With that change we can correct kernel-install (of systemd) to call new-kernel-package with --package kernel-$flavor, because the $flavor can easily be extracted from the version string. Another solution would be to name the default kernel to have a flavor "default" like SUSE does, but this does not look nice. Another solution would be a hardcoded list of flavors in kernel-install. The last solution would be to add a flavor argument to kernel-install, which has no purpose other than to pass it through to new-kernel-package.