kernel: Disable tick handling when !MULTITHREADING

The kernel timer subsystem isn't part of the !MULTITHREADING
environment (no threads to wake up, though in principle it should be
possible to support timeout callbacks with some work in the future).
Protect it against platforms that select this but still enable a timer
driver.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
1 file changed