UBUNTU: SAUCE: LSM stacking: LSM: manage task security blobs

UBUNTU: SAUCE: LSM stacking: LSM: manage task security blobs

Move management of task security blobs into the security
infrastructure. Modules are required to identify the space
they require. At this time there are no modules that use
task blobs.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>