Revert "arm: use clear_tasks_mm_cpumask()"

This reverts commit d256c994db8c145133989f1e4b996e1126dae6f3.
Revert "ARM: add assembly header for optimized hash library"

This reverts commit 06344443399d53d7c957c8b0ef26c2c60a616bf9.
Revert "lib: hash: follow-up fixups for arch hash"

This reverts commit 5d943d52e844c1c2393b3c10c8f174c26ce28988.
Revert "lib: introduce arch optimized hash library"

This reverts commit 981d397975631dabf574b2eddea2a9de45de028b.