[ofw] IWVDevice::RegisterMemory flags

[Fab Tillier]

Hi Sean,

Currently, memory registration calls MmSecureVirtualMemory in the HCA driver in the kernel, to allow caching of memory registrations to be done by middleware libraries.

MmSecureVirtualMemory does not support AWE memory ranges, however, so it would be good to add a flag for the RegisterMemory method to suppress securing the memory.  If the memory is not secured, its registration cannot be cached, but whoever calls RegisterMemory knows whether that registration will be cached or not.

Something along the lines of WV_ACCESS_LOCAL_UNSECURED would do the trick.

Thanks,
-Fab