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/pico-imx8mq_defconfig b/configs/pico-imx8mq_defconfig
index 2eeec09..c51cfcc 100644
--- a/configs/pico-imx8mq_defconfig
+++ b/configs/pico-imx8mq_defconfig
@@ -15,6 +15,7 @@
 CONFIG_SPL_FIT_GENERATOR="arch/arm/mach-imx/mkimage_fit_atf.sh"
 CONFIG_SYS_EXTRA_OPTIONS="IMX_CONFIG=arch/arm/mach-imx/imx8m/imximage.cfg"
 CONFIG_BOARD_LATE_INIT=y
+CONFIG_BOARD_EARLY_INIT_F=y
 CONFIG_SPL_BOARD_INIT=y
 CONFIG_HUSH_PARSER=y
 # CONFIG_BOOTM_NETBSD is not set