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/T2080RDB_SRIO_PCIE_BOOT_defconfig b/configs/T2080RDB_SRIO_PCIE_BOOT_defconfig
index 3274ddf..acc466e 100644
--- a/configs/T2080RDB_SRIO_PCIE_BOOT_defconfig
+++ b/configs/T2080RDB_SRIO_PCIE_BOOT_defconfig
@@ -8,6 +8,7 @@
 CONFIG_OF_STDOUT_VIA_ALIAS=y
 CONFIG_SYS_EXTRA_OPTIONS="SRIO_PCIE_BOOT_SLAVE"
 CONFIG_BOOTDELAY=10
+CONFIG_BOARD_EARLY_INIT_R=y
 CONFIG_HUSH_PARSER=y
 CONFIG_CMD_MEMTEST=y
 CONFIG_SYS_ALT_MEMTEST=y