[AArch64] paci<k>171615 auti<k>171615 assembly (#76227)

This adds the following instructions which are added in PAuthLR:
 - PACIA171615
 - PACIB171615
 - AUTIA171615
 - AUTIB171615

Also updates some encodings to match final published values.

Documentation can be found here:

https://developer.arm.com/documentation/ddi0602/2023-12/Base-Instructions



Co-authored-by: Lucas Prates <lucas.prates@arm.com>