Fix remapping VM attributes on Armada 38x

[mw]

Summary

pmap_remap_vm_attr() function requires indexes to
pte2_attr_tab as the arguments (VM_MEMATTR_).
Mistakenly, instead of them, actual values from the
table were used (PTE2_ATTR_), when applying
work-around for Marvell Armada 38x SoCs.

[mw]

Re-send patch with proper context.