Convert CONFIG_BOOTFILE to Kconfig

This converts the following to Kconfig:
   CONFIG_BOOTFILE

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/novena_defconfig b/configs/novena_defconfig
index 664a9b2..db33d11 100644
--- a/configs/novena_defconfig
+++ b/configs/novena_defconfig
@@ -52,6 +52,8 @@
 CONFIG_ENV_IS_IN_MMC=y
 CONFIG_SYS_REDUNDAND_ENVIRONMENT=y
 CONFIG_SYS_RELOC_GD_ENV_ADDR=y
+CONFIG_USE_BOOTFILE=y
+CONFIG_BOOTFILE="fitImage"
 CONFIG_VERSION_VARIABLE=y
 CONFIG_NETCONSOLE=y
 CONFIG_DM=y