QDRII VDDQ could be powered from 1V5

VDDQ could be power from 1V5. VDD must arrive before VDDQ. At present VDD is not power at 1V8 because the 1V5 is generated from a linear regulator connected to 1V8. Generating the 1V5 from a switching regulator allow to respect the timing between VDD and VDDQ.