Some kexec/kdump implementations (e.g. Xen PVOPS) on different archs could
not use default functions or require some changes in behavior of kexec/kdump
generic code. To cope with that problem kexec_ops struct was introduced.
It allows a developer to replace all or some functions and control some
functionality of kexec/kdump generic code.
Default behavior of kexec/kdump generic code is not changed.
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>