scsi: ufs : Remove delay before changing power mode

This delay is not necessary anymore due to changes that
stabalized the platform.

Change-Id: I500dd3086b3449bb795422ab44458e7a41f1cbc7
Signed-off-by: Raviv Shvili <rshvili@codeaurora.org>
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>