third_party: rename build_files to $reponame.bzl

This enables IDEs to correctly identify the filetype

Change-Id: I9e2644514f001f94abe7da92c332f95889a34380
Reviewed-on: https://review.monogon.dev/c/monogon/+/3823
Reviewed-by: Lorenz Brun <lorenz@monogon.tech>
Tested-by: Jenkins CI
diff --git a/third_party/linux-firmware/linux-firmware.bzl b/third_party/linux-firmware/linux-firmware.bzl
new file mode 100644
index 0000000..dd23722
--- /dev/null
+++ b/third_party/linux-firmware/linux-firmware.bzl
@@ -0,0 +1,3 @@
+filegroup(name = "all_files", srcs = glob(["**"]), visibility = ["//visibility:public"])
+filegroup(name = "metadata", srcs = ["WHENCE"], visibility = ["//visibility:public"])
+filegroup(name = "amd_ucode", srcs = glob(["amd-ucode/*.bin"]), visibility = ["//visibility:public"])