Kernel: Move the Storage directory to be a new directory under Devices

The Storage subsystem, like the Audio and HID subsystems, exposes Unix
device files (for example, in the /dev directory). To ensure consistency
across the repository, we should make the Storage subsystem to reside in
the Kernel/Devices directory like the two other mentioned subsystems.

Kernel/Devices/Storage/ATA/ATADiskDevice.h

@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2021, Liav A. <liavalb@hotmail.co.il>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <Kernel/Devices/Storage/ATA/ATADevice.h>
+#include <Kernel/Interrupts/IRQHandler.h>
+#include <Kernel/Locking/Mutex.h>
+
+namespace Kernel {
+
+class IDEController;
+class ATADiskDevice final : public ATADevice {
+    friend class IDEController;
+    friend class DeviceManagement;
+
+public:
+    static NonnullLockRefPtr<ATADiskDevice> create(ATAController const&, ATADevice::Address, u16 capabilities, u16 logical_sector_size, u64 max_addressable_block);
+    virtual ~ATADiskDevice() override;
+
+    // ^StorageDevice
+    virtual CommandSet command_set() const override { return CommandSet::ATA; }
+
+private:
+    ATADiskDevice(ATAController const&, Address, u16, u16, u64);
+
+    // ^DiskDevice
+    virtual StringView class_name() const override;
+};
+
+}