The 2.0 spec provides a report chunk log page that can be retrieved
using the stangard nvme get log page. This replaces the dedicated
get/put bad block table in 1.2.

This patch implements the helper functions to allow targets retrieve the
chunk metadata using get log page. It makes nvme_get_log_ext available
outside of nvme core so that we can use it form lightnvm.
Signed-off-by: NJavier González <javier@cnexlabs.com>
Signed-off-by: NMatias Bjørling <mb@lightnvm.io>
Signed-off-by: NJens Axboe <axboe@kernel.dk>