thermal: rockchip: fixes the code_to_temp for tsadc driver

We should judge the table.id[mid].code insearch algorithm on matter the
adc value increment or decrement.

Or otherwise, the temperature return the incorrect value in some cases.
[    1.438589] adc_val=402,temp=-40000
[    1.438903] adc_val=403,temp=-39375
[    1.439217] adc_val=404,temp=-38750
...
[    1.441102] adc_val=410,temp=-40000
[    1.441416] adc_val=411,temp=-34445
[    1.441737] adc_val=412,temp=-33889
...

Let's fix it right now.

Fixes commit 020ba95d ("thermal: rockchip:
Add the sort mode for adc value increment or decrement").

Reported-by: Rocky Hao <rocky.hao@rock-chips.com>
Signed-off-by: Caesar Wang <wxt@rock-chips.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Cc: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>