tools: arm64: Add a Makefile for generating sysreg-defs.h

Use a common Makefile for generating sysreg-defs.h, which will soon be
needed by perf and KVM selftests. The naming scheme of the generated
macros is not expected to change, so just refer to the canonical
script/data in the kernel source rather than copying to tools.

Co-developed-by: Jing Zhang <jingzhangos@google.com>
Signed-off-by: Jing Zhang <jingzhangos@google.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20231011195740.3349631-2-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>