UBUNTU: SAUCE: LSM stacking: make sure LSM blob align on 64 bit boundaries

UBUNTU: SAUCE: LSM stacking: make sure LSM blob align on 64 bit boundaries

BugLink: http://bugs.launchpad.net/bugs/1763062
The security->task blob reserving the first 12 bytes means that LSM
blobs don't align on 64 byte boundaries. This is not a problem
for x86 but if an LSM stores a long or ptr in its blob, then some
architectures require it be aligned to the arch word size and
will through a fault.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>