Move spinlock to separate folder

kernel/spinlock/spinlock.h

@@ -0,0 +1,21 @@
+#ifndef SPINLOCK_SPINLOCK_H_
+#define SPINLOCK_SPINLOCK_H_
+
+#include <stdatomic.h>
+#include <stdint.h>
+#include "hal/hal.h"
+
+typedef struct { atomic_bool lock; } SpinLock;
+
+// Spin more efficiently - cpu dependant
+#if defined(__x86_64__)
+# define SPINLOCK_HINT() asm volatile("pause")
+#else
+# define SPINLOCK_HINT()
+#endif
+
+void spinlock_init(SpinLock *sl);
+void spinlock_acquire(SpinLock *sl);
+void spinlock_release(SpinLock *sl);
+
+#endif // SPINLOCK_SPINLOCK_H_