AARCH64 : Fix address passed to clear cache

The entrypointExec address is modified before being passed to
clear_cache function. We do a small add/subtract for ARMv7 in
order to enable Thumb mode. This is not required for Aarch64 as
it does not support Thumb mode. Since we were not adding anything,
do not subtract as well before passing the address to clear_cache.

This was causing a crash while calling glXGetProcAddress.