scsi: ufs: keep only urgent bkops enabled during suspend

During UFS runtime suspend, we currently allow the device to perform
background operations even when device bkops status shows that bkops
operations are required but non critical. But we don't want to keep the
device active to perform the non critical bkops, instead we should put
the UFS device in sleep state to save some power.

Change-Id: Ic8d06206cd9600874ed4fdc3b7991de167394ee7
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>