dt-bindings: clk: sunxi-ccu: add compatible string for A100 CCU and R-CCU

This patch adds binding to a100's ccu clock and r-ccu clock.

Signed-off-by: Yangtao Li <frank@allwinnertech.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/5791b0a39e7ca2f1c11d3bade9ebeb7fece31230.1595572867.git.frank@allwinnertech.com