UPSTREAM: arm64: Documentation: add list of software workarounds for errata

It's not immediately obvious which hardware errata are worked around in
the Linux kernel for an arbitrary kernel tree, so add a file to keep
track of what we're working around.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

Bug: 30369029
Patchset: rework-pagetable

(cherry picked from commit 9cb9c9e5ba8453537e8e645318edf231fe54eaf9)
Signed-off-by: Jeff Vander Stoep <jeffv@google.com>
Change-Id: I139972ff6e10e12c4b4f27cd047f55b3dd8b4118