clk: sunxi: Use a single driver for all variants

Now that all of the variants use the same bind/probe functions and ops,
there is no need to have a separate driver for each variant. Since most
SoCs contain two variants (the main CCU and PRCM CCU), this saves a bit
of firmware size and RAM.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
[Andre: add F1C100s support]
Signed-off-by: Andre Przywara <andre.przywara@arm.com>