Enable extraction of debug information for kmods
    
    This hack temporary adds executable permission for the *.ko files
    during post-install stage so they are picked up by find-debuginfo.sh.
    Since the intention is to avoid changing of behaviour in non-kmod
    workloads, it's done by adding two additional brp-* scripts to the
    __spec_install_post macro when kernel_module_package is instantiated.
    
    * brp-kmod-restore-perms: New file.
    * brp-kmod-set-exec-bit: Likewise.
    * macros.kmp (%__brp_kmod_set_exec_bit, %__brp_kmod_restore_perms,
    %__kmod_brps_added): New macros.
    (%kernel_module_package): Rewrite __spec_install_post macro.
    * redhat-rpm-config.spec (Source701, Source702): Add
    brp-kmod-restore-perms and brp-kmod-set-exec-bit.
    (Requires): Add find requirement for brp-kmod-set-exec-bit.
    (%files): Explicitly list brp-* scripts for redhat-rpm-config and
    kernel-rpm-macros packages.
    
    Resolves: #2002887
    Signed-off-by: Eugene Syromiatnikov <esyr@redhat.com>