treewide: Migrate CONFIG_BOARD_EARLY_INIT_R to Kconfig

Migrate the CONFIG_BOARD_EARLY_INIT_R option to Kconfig.

Signed-off-by: Mario Six <mario.six@gdsys.cc>
diff --git a/configs/T1042RDB_PI_defconfig b/configs/T1042RDB_PI_defconfig
index 2a24d2c..acb21dd 100644
--- a/configs/T1042RDB_PI_defconfig
+++ b/configs/T1042RDB_PI_defconfig
@@ -11,6 +11,7 @@
 # CONFIG_CONSOLE_MUX is not set
 CONFIG_SYS_CONSOLE_IS_IN_ENV=y
 CONFIG_BOARD_EARLY_INIT_F=y
+CONFIG_BOARD_EARLY_INIT_R=y
 CONFIG_HUSH_PARSER=y
 CONFIG_CMD_IMLS=y
 CONFIG_CMD_GREPENV=y