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/Management.h

@@ -0,0 +1,72 @@
+/*
+ * Copyright (c) 2021-2022, Liav A. <liavalb@hotmail.co.il>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/NonnullOwnPtr.h>
+#include <AK/Platform.h>
+#include <AK/Types.h>
+#if ARCH(X86_64)
+#    include <Kernel/Arch/x86_64/VGA/IOArbiter.h>
+#endif
+#include <Kernel/Bus/PCI/Definitions.h>
+#include <Kernel/Devices/GPU/Console/Console.h>
+#include <Kernel/Devices/GPU/DisplayConnector.h>
+#include <Kernel/Devices/GPU/Generic/DisplayConnector.h>
+#include <Kernel/Devices/GPU/GenericGraphicsAdapter.h>
+#include <Kernel/Devices/GPU/VirtIO/GraphicsAdapter.h>
+#include <Kernel/Library/NonnullLockRefPtr.h>
+#include <Kernel/Memory/Region.h>
+
+namespace Kernel {
+
+class GraphicsManagement {
+
+public:
+    static GraphicsManagement& the();
+    static bool is_initialized();
+    bool initialize();
+
+    unsigned allocate_minor_device_number() { return m_current_minor_number++; };
+    GraphicsManagement();
+
+    void attach_new_display_connector(Badge<DisplayConnector>, DisplayConnector&);
+    void detach_display_connector(Badge<DisplayConnector>, DisplayConnector&);
+
+    void set_vga_text_mode_cursor(size_t console_width, size_t x, size_t y);
+    void disable_vga_text_mode_console_cursor();
+    void disable_vga_emulation_access_permanently();
+
+    LockRefPtr<Graphics::Console> console() const { return m_console; }
+    void set_console(Graphics::Console&);
+
+    void deactivate_graphical_mode();
+    void activate_graphical_mode();
+
+private:
+    void enable_vga_text_mode_console_cursor();
+
+    ErrorOr<void> determine_and_initialize_graphics_device(PCI::DeviceIdentifier const&);
+
+    void initialize_preset_resolution_generic_display_connector();
+
+    Vector<NonnullLockRefPtr<GenericGraphicsAdapter>> m_graphics_devices;
+    LockRefPtr<Graphics::Console> m_console;
+
+    // Note: This is only used when booting with kernel commandline that includes "graphics_subsystem_mode=limited"
+    LockRefPtr<GenericDisplayConnector> m_preset_resolution_generic_display_connector;
+
+    LockRefPtr<DisplayConnector> m_platform_board_specific_display_connector;
+
+    unsigned m_current_minor_number { 0 };
+
+    SpinlockProtected<IntrusiveList<&DisplayConnector::m_list_node>, LockRank::None> m_display_connector_nodes {};
+#if ARCH(X86_64)
+    OwnPtr<VGAIOArbiter> m_vga_arbiter;
+#endif
+};
+
+}