Add new dev_type:
- ump_device : Unified Memory Provider driver.
       The file_contexts entry should be
       described on a per device basis.

Minor adjustments:
- tee needs netlink socket access.
- ueventd needs to grant file operations.

Change-Id: I915304da687d3a2b9aa417e6f91ea915bd697676
Signed-off-by: rpcraig <rpcraig@tycho.ncsc.mil>

Tested on a maguro variant.

Allow reading of properties area, which is now created before init has switched contexts.  Revisit this later - we should explicitly label the properties file.