Check the HKEY firmware version (HKEY.MHKV handler), and refuse to load if
it is unknown.  Use this instead of the presence of HKEY.DHKV to detect hot
key mask capability.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>