kernel: sched: Fixed incorrect argument type of _reschedule()

This API shouldn't take a int type but instead it should take
u32_t. This argument has to be similar to irq_lock() and
irq_unlock().

Signed-off-by: Adithya Baglody <adithya.nagaraj.baglody@intel.com>
diff --git a/kernel/sched.c b/kernel/sched.c
index c61310c..44ea42e 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -430,7 +430,7 @@
 	}
 }
 
-void _reschedule(int key)
+void _reschedule(u32_t key)
 {
 #ifdef CONFIG_SMP
 	if (!_current_cpu->swap_ok) {