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
diff --git a/tools/BUILD.bazel b/tools/BUILD.bazel
index f6912cf..0de178b 100644
--- a/tools/BUILD.bazel
+++ b/tools/BUILD.bazel
@@ -18,3 +18,10 @@
     visibility = ["//visibility:public"],
     deps = [":event_log_tags"],
 )
+
+py_binary(
+    name = "check_elf_file",
+    srcs = ["check_elf_file.py"],
+    python_version = "PY3",
+    visibility = ["//visibility:public"],
+)