netdev: smsc911x: allow building on Blackfin systems

The smsc911x driver works fine on Blackfin systems, so add it to the arch
list in the Kconfig.
Signed-off-by: NMike Frysinger <vapier@gentoo.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/Kconfig

@@ -1001,7 +1001,7 @@ config SMC911X
 
 config SMSC911X
 	tristate "SMSC LAN911x/LAN921x families embedded ethernet support"
-	depends on ARM || SUPERH
+	depends on ARM || SUPERH || BLACKFIN
 	select CRC32
 	select MII
 	select PHYLIB