Kernel/Storage: Remove the ramdisk implementation

Nobody uses this because the x86 prekernel environment is corrupting the
ramdisk image prior to running the actual kernel. In the future we can
ensure that the prekernel doesn't corrupt the ramdisk if we want to
bring support back. In addition to that, we could just use a RAM based
filesystem to load whatever is needed like in Linux, without the need of
additional filesystem driver.

For the mentioned corruption problem, look at issue #9893.

Kernel/Storage/Ramdisk/Controller.h

@@ -1,36 +0,0 @@
-/*
- * Copyright (c) 2021, the SerenityOS developers.
- *
- * SPDX-License-Identifier: BSD-2-Clause
- */
-
-#pragma once
-
-#include <AK/OwnPtr.h>
-#include <AK/Types.h>
-#include <Kernel/Library/LockRefPtr.h>
-#include <Kernel/Storage/Ramdisk/Device.h>
-#include <Kernel/Storage/StorageController.h>
-#include <Kernel/Storage/StorageDevice.h>
-
-namespace Kernel {
-
-class AsyncBlockDeviceRequest;
-
-class RamdiskController final : public StorageController {
-public:
-    static NonnullLockRefPtr<RamdiskController> initialize();
-    virtual ~RamdiskController() override;
-
-    virtual LockRefPtr<StorageDevice> device(u32 index) const override;
-    virtual bool reset() override;
-    virtual bool shutdown() override;
-    virtual size_t devices_count() const override;
-    virtual void complete_current_request(AsyncDeviceRequest::RequestResult) override;
-
-private:
-    RamdiskController();
-
-    NonnullLockRefPtrVector<RamdiskDevice> m_devices;
-};
-}