lightnvm: do device max sectors boundary check first

do device max_phys_sect boundary check first, otherwise
we will allocate dma_pools for devices whose max sectors
are beyond lightnvm support and register them.

Signed-off-by: Wenwei Tao <ww.tao0320@gmail.com>
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>