block: delete module stuff from t10-pi

It is not possible to build t10-pi.ko anymore.

This file doesn't even export functions.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/216ccc79-5b80-47b2-b507-990951aa810c@p183


Signed-off-by: Jens Axboe <axboe@kernel.dk>