clk: sprd: Fix thm_parents incorrect configuration

The thm*_clk have two clock sources 32k and 250k,excluding 32m.

Fixes: af3bd365

 ("clk: sprd: Add clocks support for UMS512")
Signed-off-by: Zhifeng Tang <zhifeng.tang@unisoc.com>
Acked-by: Chunyan Zhang <zhang.lyra@gmail.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Link: https://lore.kernel.org/r/20230824092624.20020-1-zhifeng.tang@unisoc.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>