Fix ColdFire FEC warning messages

Types mismatch and implicit declaration of icache_invalid()
warning messages

Signed-off-by: TsiChung Liew <Tsi-Chung.Liew@freescale.com>
Signed-off-by: Ben Warren <biggerbadderben@gmail.com>
diff --git a/drivers/net/mcffec.c b/drivers/net/mcffec.c
index 6e69b46..7f59fa8 100644
--- a/drivers/net/mcffec.c
+++ b/drivers/net/mcffec.c
@@ -106,6 +106,10 @@
 			       unsigned char reg, unsigned short value);
 #endif
 
+#ifdef CFG_UNIFY_CACHE
+extern void icache_invalid(void);
+#endif
+
 void setFecDuplexSpeed(volatile fec_t * fecp, bd_t * bd, int dup_spd)
 {
 	if ((dup_spd >> 16) == FULL) {