Revert "[lsan] [aarch64] Add support for AArch64"

This reverts commit ea02fa45225c35613bfecab383fb526e24b74497 (r249337).

Reason: broken "ninja AsanUnitTests" on Android/AArch64.
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux/builds/20675/steps/build%20compiler-rt%20android%2Faarch64/logs/stdio

llvm-svn: 249730