scsi: ufs: ufshpb: Transform set_dirty to iterate_rgn

scsi: ufs: ufshpb: Transform set_dirty to iterate_rgn

Given a transfer length, set_dirty meticulously iterates over all the
entries, across subregions and regions if needed. Currently its only use is
to mark dirty blocks, but HCM may benefit from it as well to manage its
read counters.

Link: https://lore.kernel.org/r/20210712095039.8093-4-avri.altman@wdc.com
Reviewed-by: Daejun Park <daejun7.park@samsung.com>
Signed-off-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>