kernel: add k_object_access_revoke() system call

Does the opposite of k_object_access_grant(); the provided thread will
lose access to that kernel object.

If invoked from userspace the caller must hace sufficient access
to that object and permission on the thread being revoked access.

Fix documentation for k_object_access_grant() API to reflect that
permission on the thread parameter is needed as well.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>