scsi: ufs: don't rely on prefetched data

We were setting bActiveICCLevel attribute for UFS device only once but
type of this attribute has changed from persistent to volatile in latest
UFS device specification (v2.1). Also, UFS card specification marks this
attribute as volatile.
This means it isn't safe to rely on prefetched data (only used for
bActiveICCLevel attribute now) for both embedded & removable UFS devices
hence this change removes the code related to data prefetching.

Change-Id: I12df04d8781ede22e583db7b820753e97ee9503c
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
[cang@codeaurora.org: Resolved trivial merge conflicts]
Signed-off-by: Can Guo <cang@codeaurora.org>