CHANGELOG.md: mention the removal of BTRFS support from the kernel
CHANGELOG.md: mention the removal of BTRFS support from the kernel

Signed-off-by: Michal Mazurek <a2df1e659c9fd2578de0a26565357cb273292eeb@resin.io>

resin-os/meta-resin,resin-os/meta-resin,resin-os/meta-resin,resin-os/meta-resin