scsi: ufs: multiple queries test

Sends parallel queries with a pseudo random command. The test sends 33
queries, to make sure at least the queue depth is reached.
It tests stability in case of multiple queries.

Change-Id: I00f5992b495d17696d2ae50b510253a96ce5c979
Signed-off-by: Dolev Raviv <draviv@codeaurora.org>