arm64/cpufeature: Define hwcaps for 2025 dpISA features

arm64/cpufeature: Define hwcaps for 2025 dpISA features

The features added by the 2025 dpISA are all straightforward instruction
only features so there is no state to manage, we can just expose hwcaps to
let userspace know they are available.

F16MM is slightly odd in that the feature is FEAT_F16MM but it is discovered
via ID_AA64FPFR0_EL1.F16MM2. We follow the feature name.

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