x86: Support QEMU x86 targets

This commit introduces the initial U-Boot support for QEMU x86 targets.
U-Boot can boot from coreboot as a payload, or directly without coreboot.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
Merged in patch 'x86: qemu: Add CMD_NET to qemu-x86_defconfig
   https://patchwork.ozlabs.org/patch/479745/
diff --git a/arch/x86/cpu/qemu/qemu.c b/arch/x86/cpu/qemu/qemu.c
new file mode 100644
index 0000000..0f98476
--- /dev/null
+++ b/arch/x86/cpu/qemu/qemu.c
@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2015, Bin Meng <bmeng.cn@gmail.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/post.h>
+#include <asm/processor.h>
+
+int arch_cpu_init(void)
+{
+	int ret;
+
+	post_code(POST_CPU_INIT);
+#ifdef CONFIG_SYS_X86_TSC_TIMER
+	timer_set_base(rdtsc());
+#endif
+
+	ret = x86_cpu_init_f();
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+int print_cpuinfo(void)
+{
+	post_code(POST_CPU_INFO);
+	return default_print_cpuinfo();
+}
+
+void reset_cpu(ulong addr)
+{
+	/* cold reset */
+	x86_full_reset();
+}