ceph: update "ceph_features.h"

This updates "include/linux/ceph/ceph_features.h" so all the feature
bits defined in the user space code are defined here.

The features supported by this implementation will still differ so
that's not updated here.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>