configs: Convert CONFIG_USE_NAND to CONFIG_NAND

The DA850-EVM and OMAPL138_LCDK both use checks for CONFIG_USE_NAND.
This patch changes these checks to CONFIG_NAND which is already defined
in Kconfig.  Since the OMAPL138_LCDK already had CONFIG_NAND defined in its
defconfig, it can be deleted from configs/omapl138_lcdk.h.

Signed-off-by: Adam Ford <aford173@gmail.com>
diff --git a/include/configs/da850evm.h b/include/configs/da850evm.h
index 006cd03..973a322 100644
--- a/include/configs/da850evm.h
+++ b/include/configs/da850evm.h
@@ -148,7 +148,7 @@
 /*
  * Flash & Environment
  */
-#ifdef CONFIG_USE_NAND
+#ifdef CONFIG_NAND
 #define CONFIG_ENV_OFFSET		0x0 /* Block 0--not used by bootcode */
 #define CONFIG_ENV_SIZE			(128 << 10)
 #define	CONFIG_SYS_NAND_USE_FLASH_BBT
@@ -272,12 +272,12 @@
 #define CONFIG_CLOCKS
 #endif
 
-#ifdef CONFIG_USE_NAND
+#ifdef CONFIG_NAND
 #define CONFIG_MTD_DEVICE
 #define CONFIG_MTD_PARTITIONS
 #endif
 
-#if !defined(CONFIG_USE_NAND) && \
+#if !defined(CONFIG_NAND) && \
 	!defined(CONFIG_USE_NOR) && \
 	!defined(CONFIG_USE_SPIFLASH)
 #define CONFIG_ENV_SIZE		(16 << 10)