clk: sunxi-ng: sun5i: Add clk_set_rate_parent to the CPU clock

clk: sunxi-ng: sun5i: Add clk_set_rate_parent to the CPU clock

commit 9735ee9e3cc3ba113ac96b0368ef3f1a73092a23 upstream.

The current CPU clock is missing the option to change the rate of its
parents, leading to improper rates calculated by cpufreq, and eventually
crashes.

Fixes: 5e73761786d6 ("clk: sunxi-ng: Add sun5i CCU driver")
Reported-by: Kevin Hilman <khilman@baylibre.com>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>