clk: sunxi-ng: div: support power-of-two dividers

clk: sunxi-ng: div: support power-of-two dividers

Some clocks (for timers) on the A523 are mux-divider-gate types
with the divider being values of power-of-two.

Add a macro for these types of clocks so that we can use the divider
types instead of the M-P types without an M divider.

Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Link: https://patch.msgid.link/20250911174710.3149589-5-wens@kernel.org
Signed-off-by: Chen-Yu Tsai <wens@csie.org>