Convert CONFIG_BOARD_EARLY_INIT_F et al to Kconfig

This converts the following to Kconfig:
   CONFIG_BOARD_EARLY_INIT_F
   CONFIG_BOARD_EARLY_INIT_R

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/imx8qm_mek_defconfig b/configs/imx8qm_mek_defconfig
index dc490bc..5f68f9c 100644
--- a/configs/imx8qm_mek_defconfig
+++ b/configs/imx8qm_mek_defconfig
@@ -21,6 +21,7 @@
 CONFIG_SYS_EXTRA_OPTIONS="IMX_CONFIG=board/freescale/imx8qm_mek/imximage.cfg"
 CONFIG_BOOTDELAY=3
 CONFIG_LOG=y
+CONFIG_BOARD_EARLY_INIT_F=y
 CONFIG_SPL_BOARD_INIT=y
 CONFIG_SPL_SYS_MALLOC_SIMPLE=y
 CONFIG_SPL_SEPARATE_BSS=y