Hello Leonardo Prates,
By default the NXP BSP uses the ldo-bypass option which bypasses the internal LDO in the PMU and uses the external PMIC instead. If you will use a NXP board as reference for your design with an external PMIC you may use the ldo-bypass option as well.
There is a bit more information on this topic on page 67 of Application Note 4579:
http://www.nxp.com/files/32bit/doc/app_note/AN4579.pdf
I hope this information helps!
Regards,