fs/Kconfig: move btrfs out

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
diff --git a/fs/btrfs/Kconfig b/fs/btrfs/Kconfig
new file mode 100644
index 0000000..f8fcf99
--- /dev/null
+++ b/fs/btrfs/Kconfig
@@ -0,0 +1,18 @@
+config BTRFS_FS
+	tristate "Btrfs filesystem (EXPERIMENTAL) Unstable disk format"
+	depends on EXPERIMENTAL
+	select LIBCRC32C
+	select ZLIB_INFLATE
+	select ZLIB_DEFLATE
+	help
+	  Btrfs is a new filesystem with extents, writable snapshotting,
+	  support for multiple devices and many more features.
+
+	  Btrfs is highly experimental, and THE DISK FORMAT IS NOT YET
+	  FINALIZED.  You should say N here unless you are interested in
+	  testing Btrfs with non-critical data.
+
+	  To compile this file system support as a module, choose M here. The
+	  module will be called btrfs.
+
+	  If unsure, say N.