net: Make SMC91X selectable on other MIPS boards

RBTX4939 board has SMC91X chip and there can be other MIPS boards with
that chip.  Make SMC91X selectable on all MIPS board would be better than
enumerating each boards in Kconfig.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: jeff@garzik.org
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

drivers/net/Kconfig

@@ -888,7 +888,7 @@ config SMC91X
 	select CRC32
 	select MII
 	depends on ARM || REDWOOD_5 || REDWOOD_6 || M32R || SUPERH || \
-		SOC_AU1X00 || BLACKFIN || MN10300
+		MIPS || BLACKFIN || MN10300
 	help
 	  This is a driver for SMC's 91x series of Ethernet chipsets,
 	  including the SMC91C94 and the SMC91C111. Say Y if you want it