Convert CONFIG_NAND_DAVINCI to Kconfig

This converts the following to Kconfig:
   CONFIG_NAND_DAVINCI

Signed-off-by: Adam Ford <aford173@gmail.com>
diff --git a/configs/omapl138_lcdk_defconfig b/configs/omapl138_lcdk_defconfig
index cabea06..4a97269 100644
--- a/configs/omapl138_lcdk_defconfig
+++ b/configs/omapl138_lcdk_defconfig
@@ -35,6 +35,7 @@
 CONFIG_DM_I2C=y
 CONFIG_DM_I2C_COMPAT=y
 CONFIG_NAND=y
+CONFIG_NAND_DAVINCI=y
 CONFIG_SYS_NAND_BUSWIDTH_16BIT=y
 CONFIG_SYS_NAND_U_BOOT_LOCATIONS=y
 CONFIG_SYS_NAND_U_BOOT_OFFS=0x28000