Like all other architectures such as x86 or arm64, include KASLR offset
in VMCOREINFO ELF notes to assist in debugging. After this, we can use
crash --kaslr option to parse vmcore generated from a kaslr kernel.

Note: The crash tool needs to support --kaslr too.
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Scott Wood <oss@buserror.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>