core203: Ship grub-btrfs

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>

diff --git a/config/rootfiles/core/203/filelists/grub-btrfs b/config/rootfiles/core/203/filelists/grub-btrfs
new file mode 120000 (symlink)
index 0000000..508721b
--- /dev/null
+++ b/config/rootfiles/core/203/filelists/grub-btrfs
@@ -0,0 +1 @@
+../../../common/grub-btrfs
\ No newline at end of file