Kernel/Graphics: Remove VGA folder and its content

We never supported VGA framebuffers and that folder was a big misleading
part of the graphics subsystem.

We do support bare-bones VGA text console (80x25), but that only happens
to be supported because we can't be 100% sure we can always initialize
framebuffer so in the worst scenario we default to plain old VGA console
so the user can still use its own machine.

Therefore, the only remaining parts of VGA is in the GraphicsManagement
code to help driving the VGA text console if needed.

Kernel/Graphics/GraphicsManagement.h

@@ -13,8 +13,8 @@
 #include <Kernel/Bus/PCI/Definitions.h>
 #include <Kernel/Graphics/Console/Console.h>
 #include <Kernel/Graphics/DisplayConnector.h>
+#include <Kernel/Graphics/Generic/DisplayConnector.h>
 #include <Kernel/Graphics/GenericGraphicsAdapter.h>
-#include <Kernel/Graphics/VGA/VGACompatibleAdapter.h>
 #include <Kernel/Graphics/VirtIOGPU/GraphicsAdapter.h>
 #include <Kernel/Memory/Region.h>
 
@@ -47,15 +47,15 @@ private:
     void enable_vga_text_mode_console_cursor();
 
     bool determine_and_initialize_graphics_device(PCI::DeviceIdentifier const&);
-    bool determine_and_initialize_isa_graphics_device();
+
+    void initialize_preset_resolution_generic_display_connector();
+
     NonnullRefPtrVector<GenericGraphicsAdapter> m_graphics_devices;
     RefPtr<Graphics::Console> m_console;
 
     // Note: This is only used when booting with kernel commandline that includes "graphics_subsystem_mode=limited"
     RefPtr<GenericDisplayConnector> m_preset_resolution_generic_display_connector;
 
-    // Note: there could be multiple VGA adapters, but only one can operate in VGA mode
-    RefPtr<VGACompatibleAdapter> m_vga_adapter;
     unsigned m_current_minor_number { 0 };
 
     SpinlockProtected<IntrusiveList<&DisplayConnector::m_list_node>> m_display_connector_nodes;