[PATCH][Binutils] aarch64: rename internals related to PAuth feature to use pauth in their naming for coherency

[Nick Clifton]

Hi Matthieu,

> Commits af1bd77 and 3f4ff08 introduced the Pointer Authentication feature with internal names that don't match the actual feature name pauth. The new feature PAuth_LR 
> introduced in Armv9.5-A is an extension of the PAuth feature of Armv8.3-A. Using a different naming for it not based on the formerly "PAC" would create confusion.
> 
> Regression tested on aarch64-none-elf, and no regression found.
> 
> Ok for binutils-master? I don't have commit access so I need someone to commit on my behalf.

Approved and applied.

Cheers
   Nick