osbase/build: move efi.bzl, split and move def.bzl to their corresponding action

This is a small reorganization to make the osbase/build less dependent on each other.

Change-Id: I8c12f04f3bdc98128c5424f142f452c2e094f2e8
Reviewed-on: https://review.monogon.dev/c/monogon/+/3903
Tested-by: Jenkins CI
Reviewed-by: Lorenz Brun <lorenz@monogon.tech>
diff --git a/osbase/test/ktest/ktest.bzl b/osbase/test/ktest/ktest.bzl
index 37efd30..60a90a5 100644
--- a/osbase/test/ktest/ktest.bzl
+++ b/osbase/test/ktest/ktest.bzl
@@ -18,7 +18,8 @@
 Ktest provides a macro to run tests under a normal Metropolis node kernel
 """
 
-load("//osbase/build:def.bzl", "FSSpecInfo", "build_pure_transition", "build_static_transition", "fsspec_core_impl")
+load("//osbase/build:def.bzl", "build_pure_transition", "build_static_transition")
+load("//osbase/build/fsspec:def.bzl", "FSSpecInfo", "fsspec_core_impl")
 
 _KTEST_SCRIPT = """
 #!/usr/bin/env bash