clk: sunxi: add correct divider table for sun4i-apb0 clock

The sun4i-apb0 clock, as found on all platforms using it, is a
power-of-two-based divider clock, with a special divider of 2
for value 0.

This was causing the clock framework to incorrectly calculate
the clock rate for apb1 and related modules on sun6i and sun8i.
On sun[4/5/7]i, u-boot SPL configures the divider with value 1
for /2 divider, so no suprises there.

This patch adds a proper divider table for it, so the correct
clock rate can be calculated.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Emilio López <emilio@elopez.com.ar>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>