fadump: isolate fadump initramfs image within the default one
    
    Resolves: bz1924115
    Conflict: None
    Upstream: Fedora
    
    commit fa9201b2400565aca8165b9cd0a5151f1f94c7be (devel)
    Author: Hari Bathini <hbathini@linux.ibm.com>
    Date:   Wed Jun 23 20:06:48 2021 +0530
    
        fadump: isolate fadump initramfs image within the default one
    
        In case of fadump, the initramfs image has to be built to boot into
        the production environment as well as to offload the active crash dump
        to the specified dump target (for boot after crash). As the same image
        would be used for both boot scenarios, it could not be built optimally
        while accommodating both cases.
    
        Use --include to include the initramfs image built for offloading
        active crash dump to the specified dump target. Also, introduce a new
        out-of-tree dracut module (99zz-fadumpinit) that installs a customized
        init program while moving the default /init to /init.dracut. This
        customized init program is leveraged to isolate fadump image within
        the default initramfs image by kicking off default boot process
        (exec /init.dracut) for regular boot scenario and activating fadump
        initramfs image, if the system is booting after a crash.
    
        If squash is available, ensure default initramfs image is also built
        with squash module to reduce memory consumption in capture kernel.
    
        Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
        Signed-off-by: Kairui Song <kasong@redhat.com>
        Acked-by: Kairui Song <kasong@redhat.com>
    
    Signed-off-by: Kairui Song <kasong@redhat.com>