imx: ventana: add econfig command

The Gateworks Ventana EEPROM contains a set of configuration bits that
affect the removal of device-tree nodes that support peripherals that do not
exist on sub-loaded boards. This patch adds:
 - a structure to define a config bit name, dt node alias, bit position
 - an array of supported configuration items
 - an econfig command to get/set/list configuration bits
 - use of the array when adjusting the FDT prior to boot

Signed-off-by: Tim Harvey <tharvey@gateworks.com>
diff --git a/include/configs/gw_ventana.h b/include/configs/gw_ventana.h
index 8197a72..b991b09 100644
--- a/include/configs/gw_ventana.h
+++ b/include/configs/gw_ventana.h
@@ -95,7 +95,9 @@
 #define CONFIG_CMD_I2C
 #define CONFIG_SYS_I2C
 #define CONFIG_SYS_I2C_MXC
-#define CONFIG_SYS_I2C_SPEED		  100000
+#define CONFIG_SYS_I2C_SPEED		100000
+#define CONFIG_I2C_GSC			0
+#define CONFIG_I2C_PMIC			1
 
 /* MMC Configs */
 #define CONFIG_FSL_ESDHC
@@ -164,6 +166,7 @@
 #define CONFIG_CMD_SETEXPR
 #define CONFIG_CMD_BOOTZ
 #define CONFIG_CMD_GSC
+#define CONFIG_CMD_EECONFIG      /* Gateworks EEPROM config cmd */
 #define CONFIG_CMD_UBI
 #define CONFIG_RBTREE
 #define CONFIG_LZO