AMO should always generate store faults never load faults. We are generating both.

Created by: rosethompson

This example code from pma would cause both load and store access fault for amo access fault.

  assign PMALoadAccessFaultM     = ReadAccessM    & PMAAccessFault;
  assign PMAStoreAmoAccessFaultM = (WriteAccessM | (|CMOpM))   & PMAAccessFault;

This is probably also wrong for other faults as well. The correction is simple

  assign PMALoadAccessFaultM     =  (ReadAccessM & ~WriteAccessM)    & PMAAccessFault;
  assign PMAStoreAmoAccessFaultM = (WriteAccessM | (|CMOpM))   & PMAAccessFault;

Also need to write a regression test to show these work correctly.