- add new TEX class for WT cacheable memory
- export new TEX class to kernel as VM_MEMATTR_WT attribute
- add new aliases VM_MEMATTR_WRITE_COMBINING and
VM_MEMATTR_WRITE_BACK, it's used in DRM code
Note:
Only Cortex A8 supports WT caching in HW. On rest of Cortex CPUs,
WT requests is treated as uncacheable.
Approved by: kib (mentor)