Clean up smsc911x driver

Replace direct register address derefencing with accessor functions.
Restrict explicitly 32-bit bus-width, extend affected configurations
respectively.

Signed-off-by: Guennadi Liakhovetski <lg@denx.de>
Signed-off-by: Ben Warren <biggerbadderben@gmail.com>
diff --git a/include/configs/imx31_phycore.h b/include/configs/imx31_phycore.h
index e067b76..7e9bfb5 100644
--- a/include/configs/imx31_phycore.h
+++ b/include/configs/imx31_phycore.h
@@ -108,6 +108,7 @@
 
 #define CONFIG_DRIVER_SMC911X		1
 #define CONFIG_DRIVER_SMC911X_BASE	0xa8000000
+#define CONFIG_DRIVER_SMC911X_32_BIT	1
 
 /*
  * Miscellaneous configurable options