libkcapi: bump version to 0.14.0

libkcapi: bump version to 0.14.0

Switch from github hash to an official release.

Several upstream patches are required to build the code correctly
on all platforms supported by buildroot.

The test application now uses fork().

Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
[Arnout: Squash the two patches, MMU dependency was introduced with the
         version bump.
         Wrap assignments in libkcapi.mk differently.]
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>