efi: Refactor CPU code to be arch-specific

* Migrate some platform agnostic architecture code into
  boot/arch from efi/arch. This helps to avoid conflicts
  between kernel and boot sources as well.
* Conflicts between arch_cpu in efi and kernel code means
  bootcode really should *never* directly use kernel arch
  headers. (other platforms don't, which is why they don't
  have this same issue)
* We carefully thread any needed kernel headers (namely
  assembly helper macros) into the bootloader headers without
  mixing in the whole conflicting kernel/arch headers.
* ARM now properly get its cpu init code called, and we
  progress further into the EFI bootloader.

Change-Id: If67ec9758b5ce68563ebd9eb45d5196401911c67
Reviewed-on: https://review.haiku-os.org/c/haiku/+/2975
Reviewed-by: waddlesplash <[email protected]>

headers/private/kernel/boot/arch/arm/arch_cpu.h

@@ -0,0 +1,25 @@
+/*
+ * Copyright 2013-2020 Haiku, Inc. All rights reserved.
+ * Distributed under the terms of the MIT License.
+ */
+#ifndef EFI_BOOT_PLATFORM_EFI_ARCH_CPU_H
+#define EFI_BOOT_PLATFORM_EFI_ARCH_CPU_H
+
+
+#include <SupportDefs.h>
+#include <boot/vfs.h>
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+status_t boot_arch_cpu_init(void);
+void arch_ucode_load(BootVolume& volume);
+
+#ifdef __cplusplus
+}
+#endif
+
+
+#endif /* EFI_BOOT_PLATFORM_EFI_ARCH_CPU_H */

headers/private/kernel/boot/arch/x86/arch_cpu.h

@@ -7,6 +7,9 @@
 
 
 #include <SupportDefs.h>
+#include <boot/vfs.h>
+
+#include "../../../arch/x86/arch_cpuasm.h"
 
 
 #ifdef __cplusplus
@@ -15,15 +18,13 @@ extern "C" {
 
 
 void calculate_cpu_conversion_factor(uint8 channel);
+status_t boot_arch_cpu_init(void);
+void arch_ucode_load(BootVolume& volume);
 
 
 #ifdef __cplusplus
 }
 #endif
 
-#include <boot/vfs.h>
-
-void ucode_load(BootVolume& volume);
-
 
 #endif	/* BOOT_ARCH_CPU_H */