clk: mmp: Fix the wrong factor table for uart PLL

The suggested value in the mmp2 manual is wrong.
There are only 13 bits for numerator, but some suggested
value has 14 bits.
Fix the factor tabled and remove the unused items.

Signed-off-by: Chao Xie <chao.xie@marvell.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>