scsi: ufs: mixed long sequential

The test will verify correctness of sequential data pattern
written to the device while new data (with same pattern) is
written simultaneously.
First this test will run a long sequential write scenario.
This first stage will write the pattern that will be read
later. Second, sequential read requests will read and
compare the same data. The second stage reads, will issue in
Parallel to write requests with the same LBA and size.
NOTE: The test requires a long timeout.

The purpose of this test is to mix read and write requests on the same
LBA while checking for the read data correctness.

Change-Id: I6a437ce689b66233af3055d07a7f62f1e7b40765
Signed-off-by: Dolev Raviv <draviv@codeaurora.org>