arm64: cpufeature: Fix pointer auth hwcaps

The pointer auth hwcaps are not getting reported to userspace, as they
are missing the .matches field. Add the field back.

Fixes: 876e3c8e ("arm64/cpufeature: Pull out helper for CPUID register definitions")
Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230428132546.2513834-1-kristina.martsenko@arm.com


Signed-off-by: Will Deacon <will@kernel.org>