At boot, user threads were being granted access to the entire
app shared memory section. This is incorrect; user threads should
have no access until they are added to a memory domain, which
may contain partitions defined within it.
Change from MMU_ENTRY_USER (which grants permission at boot)
to MMU_ENTRY_RUNTIME_USER (which indicates that the pages may
be granted to user mode at runtime, but not at boot).
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>