linux-phytec-ti

clk: sunxi-ng: div: Add kerneldoc for the _ccu_div structure

The internal _ccu_div structure is meant to be embedded into other
structures to combine the various dividers and to form the clock classes
support.

Start to document those structures by using kerneldoc.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>