thermal: rockchip: fix calculation error for code_to_temp

the calculation use a global table, not their own table.
so adapt the table to the correct one.

Signed-off-by: Elaine Zhang <zhangqing@rock-chips.com>
Signed-off-by: Caesar Wang <wxt@rock-chips.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>