scsi: ufshcd: keep device rails on if link is not in OFF state

If none of the Logical Units on UFS device is power on write protected
then all UFS device power rails (VCC, VCCQ & VCCQ2) can be turned off if
UFS device is in power-off state and UFS link is in OFF state. But current
implementation would disable all device power rails even if UFS link is
not in OFF state.

Change-Id: I039e2df16eedc5c30c4473b5529e808612e53788
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>