ehci: Fix build on 64-bit

Signed-off-by: Helge Deller <deller@gmx.de>
diff --git a/src/hw/usb-ehci.c b/src/hw/usb-ehci.c
index d01fa85..3eb05f1 100644
--- a/src/hw/usb-ehci.c
+++ b/src/hw/usb-ehci.c
@@ -555,7 +555,7 @@
 
     // Allocate tds on stack (with required alignment)
     u8 tdsbuf[sizeof(struct ehci_qtd) * STACKQTDS + EHCI_QTD_ALIGN - 1];
-    struct ehci_qtd *tds = (void*)ALIGN((u32)tdsbuf, EHCI_QTD_ALIGN), *td = tds;
+    struct ehci_qtd *tds = (void*)ALIGN((unsigned long)tdsbuf, EHCI_QTD_ALIGN), *td = tds;
     memset(tds, 0, sizeof(*tds) * STACKQTDS);
 
     // Setup transfer descriptors