mv643xx_eth: Remove a stale PPC_MULTIPLATFORM

PPC_MULTIPLATFORM was killed in commit 28794d34 but this stale occurrence was
hiding the mv643xx_eth driver in some cases (e.g. Pegasos II)
Signed-off-by: NEmil Medve <Emilian.Medve@Freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/Kconfig

-
 #
 # Network device configuration
 #
@@ -2351,7 +2350,7 @@ config UGETH_TX_ON_DEMAND
 
 config MV643XX_ETH
 	tristate "Marvell Discovery (643XX) and Orion ethernet support"
-	depends on MV64360 || MV64X60 || (PPC_MULTIPLATFORM && PPC32) || PLAT_ORION
+	depends on MV64360 || MV64X60 || PPC32 || PLAT_ORION
 	select INET_LRO
 	select PHYLIB
 	help