UPSTREAM: arm64/sysreg: Add missing Pauth_LR field definitions to ID_AA64ISAR1_EL1

Add the Pauth_LR field definitions to ID_AA64ISAR1_EL1, based on
DDI0601 2023-09.

These fields aren't used yet. Adding them for completeness and
consistency (definition already exists for ID_AA64ISAR2_EL1).

Bug: 278749606
Change-Id: I47435e58f05e80680a471b821962e10694979197
Signed-off-by: Fuad Tabba <tabba@google.com>
(cherry picked from commit 3b077ad8)