clk: sunxi-ng: add support for PRCM CCUs

SoCs after A31 has a clock controller module in the PRCM part.

Support the clock controller module on H3/5 and A64 now.

Signed-off-by: Icenowy Zheng <icenowy@aosc.xyz>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>