I've found out what was going on.
With the BeagleBone, I was able to get everything working. I then compared arch/arm/configs/am335x_evm_defconfig with my configuration file and turns out this options was missing: CONFIG_MFD_TI_TSCADC.
So I rebuild my image enabling
-> Device Drivers
-> Multifunction device drivers
<*> TI ADC / Touch Screen chip support
And it worked this time. Shouldn't this information be on the wiki page?
Anyway, thank you for the support and help!
DAVI