Kernel: Move all Graphics-related code into Devices/GPU directory

Like the HID, Audio and Storage subsystem, the Graphics subsystem (which
handles GPUs technically) exposes unix device files (typically in /dev).
To ensure consistency across the repository, move all related files to a
new directory under Kernel/Devices called "GPU".

Also remove the redundant "GPU" word from the VirtIO driver directory,
and the word "Graphics" from GraphicsManagement.{h,cpp} filenames.

Kernel/Devices/GPU/VirtIO/Console.h

@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) 2021, Sahan Fernando <sahan.h.fernando@gmail.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <Kernel/Devices/GPU/Console/GenericFramebufferConsole.h>
+#include <Kernel/Devices/GPU/VirtIO/DisplayConnector.h>
+#include <Kernel/Time/TimerQueue.h>
+
+namespace Kernel::Graphics::VirtIOGPU {
+
+class Console final : public GenericFramebufferConsole {
+public:
+    static NonnullLockRefPtr<Console> initialize(VirtIODisplayConnector& parent_display_connector);
+
+    virtual void set_resolution(size_t width, size_t height, size_t pitch) override;
+    virtual void flush(size_t x, size_t y, size_t width, size_t height) override;
+    virtual void enable() override;
+
+    virtual void set_cursor(size_t x, size_t y) override;
+
+private:
+    void enqueue_refresh_timer();
+    virtual u8* framebuffer_data() override;
+
+    virtual void hide_cursor() override;
+    virtual void show_cursor() override;
+
+    Console(VirtIODisplayConnector const& parent_display_connector, DisplayConnector::ModeSetting current_resolution);
+    NonnullLockRefPtr<VirtIODisplayConnector> m_parent_display_connector;
+    bool m_dirty { false };
+};
+
+}