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/BSC9132QDS_NAND_DDRCLK100_SECURE_defconfig b/configs/BSC9132QDS_NAND_DDRCLK100_SECURE_defconfig
index f3c5ed3..49259f1 100644
--- a/configs/BSC9132QDS_NAND_DDRCLK100_SECURE_defconfig
+++ b/configs/BSC9132QDS_NAND_DDRCLK100_SECURE_defconfig
@@ -11,6 +11,7 @@
 CONFIG_SYS_EXTRA_OPTIONS="NAND_SECBOOT,SYS_CLK_100_DDR_100"
 CONFIG_BOOTDELAY=10
 CONFIG_SYS_CONSOLE_IS_IN_ENV=y
+CONFIG_BOARD_EARLY_INIT_R=y
 CONFIG_HUSH_PARSER=y
 CONFIG_CMD_IMLS=y
 CONFIG_CMD_I2C=y