ide: add configuration

CONFIG_IDE_SWAP_IO

This configuration option replaces a complex conditional
in cmd_ide.c with an explicit define to be added to SoC or
board configs.

Signed-off-by: Albert Aribaud <albert.aribaud@free.fr>
diff --git a/include/configs/r2dplus.h b/include/configs/r2dplus.h
index 8931b97..955f3ff 100644
--- a/include/configs/r2dplus.h
+++ b/include/configs/r2dplus.h
@@ -96,6 +96,7 @@
 #define CONFIG_SYS_ATA_DATA_OFFSET	0x1000	/* data reg offset */
 #define CONFIG_SYS_ATA_REG_OFFSET	0x1000	/* reg offset */
 #define CONFIG_SYS_ATA_ALT_OFFSET	0x800	/* alternate register offset */
+#define CONFIG_IDE_SWAP_IO
 
 /*
  * SuperH PCI Bridge Configration