For vmcore generated by LPAE enabled kernel, user space
utility such as crash needs additional infomation to
parse.
So this patch add arch_crash_save_vmcoreinfo as what PAE enabled
i386 linux does.
Cc: <stable@vger.kernel.org> Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Liu Hua <sdu.liu@huawei.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>