[Voyageurs] Create an abstraction for managing TRBs.

sys/voyageurs/xhci/trb.cpp

@@ -0,0 +1,10 @@
+#include "xhci/trb.h"
+
+XhciTrb CreateLinkTrb(uint64_t physical_address) {
+  return {
+      .parameter = physical_address,
+      .status = 0,
+      .type_and_cycle = 6 << 10,
+      .control = 0,
+  };
+}