and building block/blk-mq-pci.o should depend on CONFIG_BLOCK

Fixes: 973c4e37 ("blk-mq: provide a default queue mapping for PCI device")
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@fb.com>