arm: add host uart driver tests

All host tests currently pass
Some async refactors may not work well on device, will try later

arm/lock.h

@@ -1,5 +1,6 @@
 #pragma once
 
+#ifndef __x86_64__
 #include "aum1_cm1.h"
 
 struct InterruptLock {
@@ -11,3 +12,12 @@ struct InterruptLock {
         __set_PRIMASK(old_primask);
     }
 };
+#else  // __x86_64__
+#include <mutex>
+
+struct InterruptLock {
+    static std::recursive_mutex m;
+    InterruptLock() { m.lock(); }
+    ~InterruptLock() { m.unlock(); }
+};
+#endif  // __x86_64__