bsg: bind bsg to request_queue instead of gendisk

This patch binds bsg devices to request_queue instead of gendisk. Any
objects (like transport entities) can define own request_handler and
create own bsg device.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

diff --cc block/bsg.c
Simple merge

diff --cc block/ll_rw_blk.c
Simple merge

diff --cc include/linux/blkdev.h
Simple merge

diff --cc include/linux/bsg.h
Simple merge

diff --cc include/linux/genhd.h
Simple merge