Kernel: Add basic HPET support to replace PIT if exists

This works same way as the PIT implementation; calls Scheduler every
milli second.

kernel/include/kernel/Timer/HPET.h

@@ -0,0 +1,27 @@
+#pragma once
+
+#include <kernel/Timer/Timer.h>
+
+namespace Kernel
+{
+
+	class HPET final : public Timer
+	{
+	public:
+		static BAN::ErrorOr<BAN::UniqPtr<HPET>> create();
+
+		virtual uint64_t ms_since_boot() const override;
+
+	private:
+		HPET() = default;
+		BAN::ErrorOr<void> initialize();
+
+		void write_register(ptrdiff_t reg, uint64_t value) const;
+		uint64_t read_register(ptrdiff_t reg) const;
+
+	private:
+		uint64_t m_counter_tick_period_fs { 0 };
+		vaddr_t m_mmio_base { 0 };
+	};
+
+}