scsi: ufs: fix broken hibern8_on_idle sysfs nodes

Setting 0 to auto hibern8 delay means turning auto hibern8 off, then the
link shall be kept active even when clock gating kicks in. To keep link
active, both device ref clock and UNIPRO clock should be kept ON when
disable clocks during clock gating.

Change-Id: If2c70eff7cf99928aabe46f311e7413c57af0ba7
Signed-off-by: Can Guo <cang@codeaurora.org>