arm64/sysreg: Align pointer auth enumeration defines with architecture

The defines used for the pointer authentication feature enumerations do not
follow the naming convention we've decided to use where we name things
after the architecture feature that introduced. Prepare for generating the
defines for the ISA ID registers by updating to use the feature names.
No functional changes.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220704170302.2609529-10-broonie@kernel.org


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