Kernel: Send EOI after handling the interrupt

There is no need to send it prior to handling. This required us to not
yield from HPET/PIT irq so that the EOI actually gets sent

kernel/include/kernel/Scheduler.h

@@ -58,7 +58,7 @@ namespace Kernel
 		BAN::ErrorOr<void> initialize();
 
 		void reschedule(YieldRegisters*);
-		void reschedule_if_idle();
+		void reschedule_if_needed();
 
 		void on_timer_interrupt();
 		void on_yield(YieldRegisters*);
@@ -118,6 +118,8 @@ namespace Kernel
 
 		bool m_should_calculate_max_load_threads { true };
 
+		bool m_has_pending_reschedule { false };
+
 		Thread* m_idle_thread { nullptr };
 
 		friend class ThreadBlocker;