feat: initial locking etc.

kernel/libk/syscall.c

@@ -30,3 +30,7 @@ void syscall_yield_job() {
 void syscall_yield_irq(uint16_t irq) {
     syscall2(SYSCALL_YIELD_IRQ, irq );
 }
+
+void syscall_job_suspend() {
+    syscall1(SYSCALL_SUSPEND);
+}