chore: general cleanup in code (removed unused includes and cosmetic stuff

Kernel/Include/Arch/GIC.h

@@ -1,6 +1,5 @@
 #pragma once
 #include <Types.h>
-#include <Arch/IO.h>
 #include <Arch/Exceptions.h>
 
 enum {

Kernel/Include/Arch/Timer.h

@@ -2,8 +2,10 @@
 #include <Types.h>
 #include <Arch/Exceptions.h>
 
-static const UInt64 kTimerFrequency = 1000; // 1ms
-static const UInt8 kTimerIRQ = 27;
+enum {
+    kTimerFrequency = 1000, // 1ms
+    kTimerIRQ = 27,
+};
 
 void TimerInitialize();
 void TimerReset(UInt64 interval);