boot/efi/arm64: implement arch_convert_kernel_args()

Empty function for now as no arch-specific calls to
fix_address() needed on arm64.

Change-Id: Ifef100c132eac29a2b763e06bf1efd695b284851
Reviewed-on: https://review.haiku-os.org/c/haiku/+/4894
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>

src/system/boot/platform/efi/arch/arm64/arch_start.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2019-2020 Haiku, Inc. All rights reserved.
+ * Copyright 2019-2022 Haiku, Inc. All rights reserved.
  * Released under the terms of the MIT License.
  */
 
@@ -15,6 +15,13 @@ extern "C" void arch_enter_kernel(struct kernel_args *kernelArgs,
 	addr_t kernelEntry, addr_t kernelStackTop);
 
 
+void
+arch_convert_kernel_args(void)
+{
+	// empty
+}
+
+
 void
 arch_start_kernel(addr_t kernelEntry)
 {