clk: hi3660: Mark clk_gate_ufs_subsys as critical

clk_gate_ufs_subsys is a system bus clock, turning off it will
introduce lockup issue during system suspend flow.  Let's mark
clk_gate_ufs_subsys as critical clock, thus keeps it on during
system suspend and resume.

Fixes: d374e6fd ("clk: hisilicon: Add clock driver for hi3660 SoC")
Cc: stable@vger.kernel.org
Cc: Zhong Kaihua <zhongkaihua@huawei.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Zhangfei Gao <zhangfei.gao@linaro.org>
Suggested-by: Dong Zhang <zhangdong46@hisilicon.com>
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>