amd64: enable options NUMA ing GENERIC and MINIMAL

[Kevin Bowling]

-CURRENT users, in svn rS338602, 'options NUMA' has just been enabled
for amd64 GENERIC and MINIMAL kernels.

This should provide good effect to systems with more than one physical
CPU with associated memory, certain high core count Intel chips when
configured to use Cluster-on-Die or Sub-NUMA-Clustering, and recent
AMD products with multiple chiplets like Thread Ripper and EPYC.  If
you have a single domain system, there is no expected change.

If you have such NUMA machines, early testing would be greatly
appreciated in order to ensure the quality and stability of the 12.0
release.

You can confirm configuration of NUMA domains with 'sysctl
vm.ndomains', example output:
vm.ndomains: 2

This work was sponsored by Dell EMC Isilon and Netflix and led by Jeff
Roberson.  Some folks have participated for a long time in bi-weekly
calls and stabilization.  It is known to be used in production
configurations for some time at Netflix and Limelight Networks.

If you encounter any issues where you suspect this is the root cause,
please disable 'options NUMA' in the kernel configuration and
reproduce before reporting as such.

This would be a good time to audit your kernel config if copied from
GENERIC and consider if you can instead use 'include GENERIC-NODEBUG'
to only track local modifications.

Regards,
Kevin Bowling