move arch include dir

kernel-src/include/x86-64/arch/cpu.h

@@ -0,0 +1,24 @@
+#ifndef _CPU_H
+#define _CPU_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include <arch/msr.h>
+#include <arch/ist.h>
+
+typedef struct {
+	uint64_t gdt[7];
+	ist_t ist;
+	int lapicid;
+} cpu_t;
+
+static inline cpu_t *_cpu() {
+	return (cpu_t *)rdmsr(MSR_GSBASE);
+}
+
+static inline void cpu_set(cpu_t *ptr) {
+	wrmsr(MSR_GSBASE, (uint64_t)ptr);
+}
+
+#endif