Update kernels 5.10 and 5.15

[larvacea]

Description of changes: Update kernel-5.10 to upstream 5.10.227 and kernel-5.15 to 5.15.168.

Patch changes:

• In 5.10, improve nvme-passthrough handling of metadata.
• In both kernels, revert earlier patches to ext4 filesystem code.

Configuration changes:

• 5.10, aarch64: disable AMD GPU
• enable CONFIG_PROC_MEM_ALWAYS_FORCE

Testing done:

aws-ecs-1 (kernel 5.10) and aws-k8s-1.25 (kernel 5.15) AMIs boot on both architectures.

Terms of contribution:

By submitting this pull request, I agree that this contribution is dual-licensed under the terms of both the Apache License, version 2.0, and the MIT license.

[larvacea]

pr-diffs.txt

The complete (and I hope very dull) story on config changes.