Kernel: Fix interrupt system

I had not understood how MSIs work and I was unnecessarily routing them
through IOAPIC. This is not necessary and should not be done :D

Also MSIs were reserving interrupts that IOAPIC was capable of
generating. Now IOAPIC and MSIs use different set of interrupts so
IOAPIC can use more interrupts if needed.

kernel/kernel/Timer/HPET.cpp

@@ -223,7 +223,7 @@ namespace Kernel
 
 		TRY(InterruptController::get().reserve_irq(0));
 		set_irq(0);
-		enable_interrupt();
+		InterruptController::get().enable_irq(0);
 
 		return {};
 	}

kernel/kernel/Timer/PIT.cpp

@@ -48,7 +48,7 @@ namespace Kernel
 
 		MUST(InterruptController::get().reserve_irq(PIT_IRQ));
 		set_irq(PIT_IRQ);
-		enable_interrupt();
+		InterruptController::get().enable_irq(PIT_IRQ);
 	}
 
 	void PIT::handle_irq()