feat: make kernel architecture-agnostic; primitive work on arm port

kernel/src/Drivers/USB/Bluetooth/IntelFirmware.cpp

@@ -12,13 +12,14 @@
 */
 
 #include "IntelFirmware.hpp"
+#include <Arch/Cpu.hpp>
 #include "Hci.hpp"
 #include <Fs/Vfs.hpp>
 #include <Memory/Heap.hpp>
 #include <Terminal/Terminal.hpp>
 #include <CppLib/Stream.hpp>
 #include <Libraries/Memory.hpp>
-#include <Timekeeping/ApicTimer.hpp>
+#include <Timekeeping/Timer.hpp>
 
 using namespace Kt;
 
@@ -475,7 +476,7 @@ namespace Drivers::USB::Bluetooth {
         }
         Fs::Vfs::ReadBackendFile(file, fw, 0, size);
         Fs::Vfs::CloseBackendFile(file);
-        asm volatile("" ::: "memory");
+        Arch::CompilerBarrier();
 
         // 4. Run the secure download + boot sequence.
         bool ok = DownloadImage(fw, size, ver, cnvi, cnvr);