arm64: make isttbrXaddr() noinstr-safe
This is an automated ID intended to aid in discovery of potential security vulnerabilities. The actual impact and attack plausibility have not yet been proven. This ID is fixed in Linux Kernel version v5.15.86 by commit 9d05c20b0ac97a688f6f6747da45b4d1e287b806. For more details please see the references link.