clk: sprd: Hold reference returned by of_get_parent()

We should hold the reference returned by of_get_parent() and use it
to call of_node_put() for refcount balance.

Fixes: f95e8c79 ("clk: sprd: support to get regmap from parent node")
Signed-off-by: Liang He <windhl@126.com>
Link: https://lore.kernel.org/r/20220704004729.272481-1-windhl@126.com


Reviewed-by: Orson Zhai <orsonzhai@gmail.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>