Kernel: Implement RamdiskDevice

Author: https://github.com/boricj
Commit: 225957283e
Pull-request: https://github.com/SerenityOS/serenity/pull/5028
Reviewed-by: https://github.com/awesomekling

Kernel/Storage/StorageController.h

@@ -46,6 +46,7 @@ class StorageController : public RefCounted<StorageController> {
     AK_MAKE_ETERNAL
 public:
     enum class Type : u8 {
+        Ramdisk,
         IDE,
         NVMe
     };