x86: Add common Intel code for SPL

Add an implementation of arch_cpu_init_f() so that the x86 SPL code builds
and identifies the CPU.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

arch/x86/cpu/intel_common/Makefile

@@ -14,3 +14,9 @@ ifndef CONFIG_TARGET_EFI_APP
 obj-y += microcode.o
 endif
 obj-y += pch.o
+
+ifdef CONFIG_SPL
+ifndef CONFIG_SPL_BUILD
+obj-y += cpu_from_spl.o
+endif
+endif

arch/x86/cpu/intel_common/cpu_from_spl.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2016 Google, Inc
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <asm/cpu_common.h>
+#include <asm/intel_regs.h>
+#include <asm/lapic.h>
+#include <asm/lpc_common.h>
+#include <asm/msr.h>
+#include <asm/mtrr.h>
+#include <asm/post.h>
+#include <asm/microcode.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+int arch_cpu_init(void)
+{
+	int ret;
+
+	ret = x86_cpu_reinit_f();
+
+	return ret;
+}