net: Add SMC911X driver to Kconfig, convert

We add the various SMC91XX symbols to drivers/net/Kconfig and then this
converts the following to Kconfig:
   CONFIG_SMC911X
   CONFIG_SMC911X_BASE
   CONFIG_SMC911X_16_BIT
   CONFIG_SMC911X_32_BIT

Signed-off-by: Adam Ford <aford173@gmail.com>
[trini: Apply to the rest of the tree, re-squash old and new patch]
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/mx31pdk_defconfig b/configs/mx31pdk_defconfig
index 3fcc0c0..0884caf 100644
--- a/configs/mx31pdk_defconfig
+++ b/configs/mx31pdk_defconfig
@@ -18,3 +18,7 @@
 # CONFIG_MMC is not set
 CONFIG_NAND=y
 CONFIG_NAND_MXC=y
+CONFIG_NETDEVICES=y
+CONFIG_SMC911X=y
+CONFIG_SMC911X_BASE=0xB6000000
+CONFIG_SMC911X_32_BIT=y