Kernel: Move TrapFrame into its own header on aarch64

Kernel/Arch/aarch64/TrapFrame.h

@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) 2018-2021, Andreas Kling <kling@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/Types.h>
+
+#include <AK/Platform.h>
+
+namespace Kernel {
+
+struct TrapFrame {
+    u64 x[31];     // Saved general purpose registers
+    u64 spsr_el1;  // Save Processor Status Register, EL1
+    u64 elr_el1;   // Exception Link Reigster, EL1
+    u64 tpidr_el1; // EL0 thread ID
+    u64 sp_el0;    // EL0 stack pointer
+};
+
+}