Add check_elf_file to BUILD.bazel

In supporting cc_prebuilt_binary building with Bazel, we
need to enable Bazel to be able to introspect and build
the check_elf_files.py tool, originally built via make

Bug: 241415823
Test: b build '//build/make/tools:check_elf_file'
Change-Id: I4eeae86f683c678809e84edc2fee88f9d2436f9f