clk: sunxi: implement clock driver for suniv f1c100s

The f1c100s has a clock tree similar to those of other sunxi parts.
Add support for it.

Signed-off-by: George Hilliard <thirtythreeforty@gmail.com>
Signed-off-by: Yifan Gu <me@yifangu.com>
Acked-by: Sean Anderson <seanga2@gmail.com>
[Andre: add PIO and I2C]
Signed-off-by: Andre Przywara <andre.przywara@arm.com>