selinux: remove userland security class and permission definitions

selinux: remove userland security class and permission definitions

Remove userland security class and permission definitions from the kernel
as the kernel only needs to use and validate its own class and permission
definitions and userland definitions may change.

Signed-off-by:  Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>