Kernel: Renable UHCIController on 64-bit processors

Author: https://github.com/Hendiadyoin1
Commit: 0b04363b01
Pull-request: https://github.com/SerenityOS/serenity/pull/5679
Reviewed-by: https://github.com/ADKaster
Reviewed-by: https://github.com/linusg

Kernel/init.cpp

@@ -274,9 +274,7 @@ void init_stage2(void*)
     }
 
     // FIXME: This should not be i386-specific.
-#if ARCH(I386)
     USB::UHCIController::detect();
-#endif
 
     DMIExpose::initialize();