MPC5xxx: fix some compiler warnings in USB code

Fix the following warnings:
- usb.c:xx: warning: function declaration isn't a prototype
- usb_ohci.c:xxx: warning: passing argument 1 of '__fswab32' makes integer
  from pointer wihtout a cast

Signed-off-by: Martin Krause <martin.krase@tqs.de>
diff --git a/drivers/usb_ohci.c b/drivers/usb_ohci.c
index f0a37b2..14984a5 100644
--- a/drivers/usb_ohci.c
+++ b/drivers/usb_ohci.c
@@ -669,7 +669,7 @@
 				ed_p = &(((ed_t *)ed_p)->hwNextED))
 					inter = ep_rev (6, ((ed_t *)ed_p)->int_interval);
 			ed->hwNextED = *ed_p;
-			*ed_p = m32_swap(ed);
+			*ed_p = m32_swap((unsigned long)ed);
 		}
 		break;
 	}
@@ -687,11 +687,11 @@
 
 		/* ED might have been unlinked through another path */
 		while (*ed_p != 0) {
-			if (((struct ed *)m32_swap (ed_p)) == ed) {
+			if (((struct ed *)m32_swap ((unsigned long)ed_p)) == ed) {
 				*ed_p = ed->hwNextED;
 				break;
 			}
-			ed_p = & (((struct ed *)m32_swap (ed_p))->hwNextED);
+			ed_p = & (((struct ed *)m32_swap ((unsigned long)ed_p))->hwNextED);
 		}
 	}
 }