Revert "arm64: errata: Add Cortex-A520 speculative unprivileged load workaround"

This reverts commit 6e3ae292 which is
commit 471470bc upstream.

This change breaks the Android ABI, if it is needed in the future, it
can be brought back in an abi-safe way.

Change-Id: I1f79c77da78e5a0edde2bdebb862e4c9855175a0
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>