clk_cifout is derived from clk_cifout_src through an integer divider
limited to 32. clk_cifout_src is a child of either cpll, gpll or npll
without any possibility of a divider of any sort. The default clock
parent is cpll.

Let's allow clk_cifout to ask its parent clk_cifout_src to reparent in
order to find the real closest possible rate for clk_cifout and not one
derived from cpll only.

Cc: stable@vger.kernel.org # 4.10+
Fixes: fd8bc829 ("clk: rockchip: fix the rk3399 cifout clock")
Signed-off-by: Quentin Schulz <quentin.schulz@theobroma-systems.com>
Link: https://lore.kernel.org/r/20221117-rk3399-cifout-set-rate-parent-v1-0-432548d04081@theobroma-systems.comSigned-off-by: Heiko Stuebner <heiko@sntech.de>