uboot: (firmwareOdroidC2/C4) don't invoke patch tool, use patches = [] instead

https://github.com/NixOS/nixpkgs/blob/master/pkgs/stdenv/generic/setup.sh#L948
this can do it nicely.

Signed-off-by: Anton Arapov <anton@deadbeef.mx>

pkgs/common-updater/git-updater.nix

@@ -0,0 +1,21 @@
+{ lib
+, genericUpdater
+, common-updater-scripts
+}:
+
+{ pname
+, version
+, attrPath ? pname
+, ignoredVersions ? ""
+, rev-prefix ? ""
+, odd-unstable ? false
+, patchlevel-unstable ? false
+# an explicit url is needed when src.meta.homepage or src.url don't
+# point to a git repo (eg. when using fetchurl, fetchzip, ...)
+, url ? null
+}:
+
+genericUpdater {
+  inherit pname version attrPath ignoredVersions rev-prefix odd-unstable patchlevel-unstable;
+  versionLister = "${common-updater-scripts}/bin/list-git-tags ${lib.optionalString (url != null) "--url=${url}"}";
+}