clk: ingenic/jz4740: Fix incorrect dividers for main clocks

The main clocks (cclk, hclk, pclk, mclk, lcd) were using
incorrect dividers, and thus reported an incorrect rate.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>