mpc5200: Fix Kconfig dependancies on MPC5200 FEC device driver

When not building an arch/powerpc kernel, the mpc5200 FEC driver depends
on some symbols which are not defined (BESTCOMM & BESTCOMM_FEC).

This patch flips around the dependancy logic so that it cannot be
selected unless BESTCOMM_FEC is selected first.  Kconfig stops
complaining this way.

Also, the driver only works for arch/powerpc (not arch/ppc) anyway so
it should depend on PPC_MERGE also.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index 867cb73..5f800a6 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -1883,9 +1883,7 @@
 
 config FEC_MPC52xx
 	tristate "MPC52xx FEC driver"
-	depends on PPC_MPC52xx
-	select PPC_BESTCOMM
-	select PPC_BESTCOMM_FEC
+	depends on PPC_MERGE && PPC_MPC52xx && PPC_BESTCOMM_FEC
 	select CRC32
 	select PHYLIB
 	---help---