btrfs-tools: Update to 5.12

Add PACKAGECONFIG for zoned block devices. Leave disabled by default, as
this requires a recent kernel.

License-Update: libbtrfsutil was relicensed to LGPLv2.1+: https://git.kernel.org/pub/scm/linux/kernel/git/kdave/btrfs-progs.git/commit/?id=9e30f779e3cbf12a88ebe309ee371851fdfd3aa0



Signed-off-by: Robert Joslyn <robert.joslyn@redrectangle.org>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>