lightnvm: move device L2P detection to core

A 1.2 device is able to manage the logical to physical mapping
table internally or leave it to the host.

A target only supports one of those approaches, and therefore must
check on initialization. Move this check to core to avoid each target
implement the check.

Signed-off-by: Matias Bjørling <mb@lightnvm.io>
Signed-off-by: Jens Axboe <axboe@kernel.dk>