backport of arm64: mte: move register initialization to C

Hello stable,

please backport the following commits to 5.15-stable:

commit 973b9e37330656dec719ede508e4dc40e5c2d80c upstream.

Please note that the extra backport below can be avoided with a trivial change in the above patch. Let me know if that's preferable.

Cc: stable@vger.kernel.org # 5.15.y: e921da6: arm64/mm: Consolidate TCR_EL1 fields Signed-off-by: Evgenii Stepanov eugenis@google.com