net: fix IBM EMAC driver after rename.

In commit 9aa3283595451ca093500ff0977b106e1f465586 (ehea/ibm*: Move the
IBM drivers) the IBM_NEW_EMAC* were renames to IBM_EMAC*

The conversion was incomplete so that even if the driver was added to
the .config it wasn't built, but there were no errors).  In this commit
we also update the various defconfigs that use EMAC to use the new
Kconfig symbol, and explicitly add the NET_VENDOR_IBM guard.

We do not explicitly select the Kconfig dependencies, as this would force
EMAC on.  Doing it in the defconfig allows more flexibility.

Tested on a canyondlands board.

Signed-off-by: Tony Breeds <tony@bakeyournoodle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/arch/powerpc/configs/ppc40x_defconfig b/arch/powerpc/configs/ppc40x_defconfig
index bfd634b..7cb703b 100644
--- a/arch/powerpc/configs/ppc40x_defconfig
+++ b/arch/powerpc/configs/ppc40x_defconfig
@@ -50,8 +50,9 @@
 CONFIG_BLK_DEV_RAM_SIZE=35000
 CONFIG_XILINX_SYSACE=m
 CONFIG_NETDEVICES=y
-CONFIG_NET_ETHERNET=y
-CONFIG_IBM_NEW_EMAC=y
+CONFIG_ETHERNET=y
+CONFIG_NET_VENDOR_IBM=y
+CONFIG_IBM_EMAC=y
 # CONFIG_INPUT is not set
 CONFIG_SERIO=m
 # CONFIG_SERIO_I8042 is not set