ext: Revert "base: Use system libelf instead of ext"

This reverts commit bbb32ca1ef8eb8249cdca72be6171b94f61bd62e,
which tells scons to use the system's libelf instead of
ext/libelf.

Signed-off-by: Hoa Nguyen <hoanguyen@ucdavis.edu>
Change-Id: I3bb3e62f2ef0fbc72983c221d5570edb4b35d157
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/33940
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
4 files changed