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/xilinx_zynqmp_zcu102_revB_defconfig b/configs/xilinx_zynqmp_zcu102_revB_defconfig
index f3b05d1..e6530fb 100644
--- a/configs/xilinx_zynqmp_zcu102_revB_defconfig
+++ b/configs/xilinx_zynqmp_zcu102_revB_defconfig
@@ -15,6 +15,7 @@
 CONFIG_SPL_LOAD_FIT=y
 # CONFIG_DISPLAY_CPUINFO is not set
 # CONFIG_DISPLAY_BOARDINFO is not set
+CONFIG_BOARD_EARLY_INIT_R=y
 CONFIG_SPL_OS_BOOT=y
 CONFIG_SPL_RAM_SUPPORT=y
 CONFIG_SPL_RAM_DEVICE=y