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/pm9263_defconfig b/configs/pm9263_defconfig
index 1a3de43..d8d2d10 100644
--- a/configs/pm9263_defconfig
+++ b/configs/pm9263_defconfig
@@ -6,6 +6,7 @@
 CONFIG_BOOTDELAY=3
 # CONFIG_CONSOLE_MUX is not set
 CONFIG_SYS_CONSOLE_IS_IN_ENV=y
+CONFIG_BOARD_EARLY_INIT_F=y
 CONFIG_SYS_PROMPT="u-boot-pm9263> "
 # CONFIG_CMD_BDI is not set
 # CONFIG_CMD_IMI is not set