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/mscc_serval_defconfig b/configs/mscc_serval_defconfig
index e35219e..e423fc4 100644
--- a/configs/mscc_serval_defconfig
+++ b/configs/mscc_serval_defconfig
@@ -16,6 +16,7 @@
 CONFIG_BOOTARGS="console=ttyS0,115200"
 CONFIG_LOGLEVEL=7
 CONFIG_DISPLAY_CPUINFO=y
+CONFIG_BOARD_EARLY_INIT_R=y
 CONFIG_SYS_PROMPT="serval # "
 # CONFIG_CMD_BDI is not set
 # CONFIG_CMD_CONSOLE is not set