arm64 crashkernel fails to boot on acpi-only machines due to ACPI regions being no longer mapped as NOMAP

[Dave Young]

[snip]
> > > Well, we may be able to change pr_warn() to pr_warn_once() here, but
> > > I hope that adding "numa=off" to kernel command line should also work.
> > 
> > Hmm, adding "numa=off" to crashkernel bootargs works, and TBH it was
> > my initial thought process as well, but I am not sure if this will
> > cause any regressions on aarch64 systems which use crashdump feature.
> 
> It should be fine since we use numa=off by default for all other arches
> ie. x86, ppc64 and s390. Actually disabling numa in kdump kernel can save
> mm component memory usage. 
> 

Forgot to say I means in RHEL and Fedora we use numa=off for kdump..