convert the mmc driver to use blk_mq_alloc_disk

Hi Ulf,

can you take a look at this series which converts the mmc driver to the
new blk_mq_alloc_disk interface.  It is based upon Jens' for-5.14/block
or for-next trees.

Diffstat:
 block.c |   28 ++++------------------------
 queue.c |   23 ++++++++++-------------
 queue.h |    2 +-
 3 files changed, 15 insertions(+), 38 deletions(-)