Migrate CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG to Kconfig

Convert CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG to Kconfig

Signed-off-by: Alex Kiernan <alex.kiernan@gmail.com>
Reviewed-by: Lukasz Majewski <lukma@denx.de>
Reviewed-by: Petr Vorel <petr.vorel@gmail.com>
Reviewed-by: Petr Vorel <petr.vorel at gmail.com>
diff --git a/configs/omap4_panda_defconfig b/configs/omap4_panda_defconfig
index 9fb4aec..7e01646 100644
--- a/configs/omap4_panda_defconfig
+++ b/configs/omap4_panda_defconfig
@@ -26,6 +26,7 @@
 CONFIG_ENV_IS_IN_FAT=y
 CONFIG_ENV_FAT_INTERFACE="mmc"
 CONFIG_ENV_FAT_DEVICE_AND_PART="0:1"
+CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG=y
 CONFIG_MMC_OMAP_HS=y
 CONFIG_CONS_INDEX=3
 CONFIG_SYS_NS16550=y