Convert CONFIG_BOARD_EARLY_INIT_F to Kconfig

This converts the following to Kconfig:
   CONFIG_BOARD_EARLY_INIT_F

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/tbs2910_defconfig b/configs/tbs2910_defconfig
index 9fefa5f..edcf054 100644
--- a/configs/tbs2910_defconfig
+++ b/configs/tbs2910_defconfig
@@ -6,6 +6,7 @@
 CONFIG_FIT=y
 CONFIG_BOOTDELAY=3
 CONFIG_PRE_CON_BUF_ADDR=0x7c000000
+CONFIG_BOARD_EARLY_INIT_F=y
 CONFIG_HUSH_PARSER=y
 CONFIG_SYS_PROMPT="Matrix U-Boot> "
 CONFIG_CMD_BOOTZ=y