Convert CONFIG_SYS_I2C_DAVINCI to Kconfig

This converts the following to Kconfig:
   CONFIG_SYS_I2C_DAVINCI

Signed-off-by: Adam Ford <aford173@gmail.com>
diff --git a/configs/omapl138_lcdk_defconfig b/configs/omapl138_lcdk_defconfig
index 8eedc10..e8c6cf0 100644
--- a/configs/omapl138_lcdk_defconfig
+++ b/configs/omapl138_lcdk_defconfig
@@ -36,6 +36,7 @@
 CONFIG_DM=y
 CONFIG_DM_I2C=y
 CONFIG_DM_I2C_COMPAT=y
+CONFIG_SYS_I2C_DAVINCI=y
 CONFIG_NAND=y
 CONFIG_NAND_DAVINCI=y
 CONFIG_SYS_NAND_BUSWIDTH_16BIT=y