x86_64: initialise device subsystem during boot

arch/x86_64/init.c

@@ -1,4 +1,5 @@
 #include <socks/pmap.h>
+#include <socks/device.h>
 #include <socks/clock.h>
 #include <socks/types.h>
 #include <socks/object.h>
@@ -80,6 +81,7 @@ int ml_init(uintptr_t arg)
 	object_bootstrap();
 	sched_init();
 
+	device_init();
 	acpi_init();
 
 	ml_int_enable();