arm64/sysreg: Initial unsigned annotations for ID registers

In order to allow the simplification of way we declare hwcaps annotate
most of the unsigned fields in the identification registers as such. This
is not a complete annotation, it does cover all the cases where we already
annotate signedness of the field in the hwcaps and some others which I
happened to look at and seemed clear but there will be more and nothing
outside the identification registers was even looked at.

Other fields can be annotated as incrementally as people have the time and
need to do so.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20221207-arm64-sysreg-helpers-v4-3-25b6b3fb9d18@kernel.orgSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>