* rk_cru is a cru driver that needs to be subclassed by
the real CRU driver
* rk_clk_pll handle the pll type clock on RockChip SoC, it's only read
only for now.
* rk_clk_composite handle the different composite clock types (with gate,
with mux etc ...)
* rk_clk_gate handle the RockChip gates
* rk_clk_mux handle the RockChip muxes (unused for now)
* Only clocks for supported devices are supported for now, the rest will be
added when driver support comes
* The assigned-clock* property are not handled for now so we rely a lot on the
bootloader to setup some initial values for some clocks.
2a3d5e3364