Contrary to what the datasheet says, the pre divider doesn't seem to be
incremented by one in the PLL2, but just uses the value from the register,
with 0 being a bypass.

This fixes the audio playing too fast.

Since we now have the same pre-divider flags, and the only difference with
the A10 is the post-divider offset, also remove the structure to just pass
the offset as an argument.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Fixes: eb662f85 ("clk: sunxi: pll2: Add A13 support")
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>