corstone1000: set kernel_addr based on boot_idx

We need to distinguish between boot banks and from which
partition to load the kernel+initramfs to memory.

For that, fetch the boot index, fetch the correspondent
partition, calculate the correct kernel address and
then set the env variable kernel_addr with that value.

Signed-off-by: Rui Miguel Silva <rui.silva@linaro.org>
diff --git a/configs/corstone1000_defconfig b/configs/corstone1000_defconfig
index 2d39104..5be5335 100644
--- a/configs/corstone1000_defconfig
+++ b/configs/corstone1000_defconfig
@@ -20,6 +20,7 @@
 CONFIG_LOGLEVEL=7
 # CONFIG_DISPLAY_CPUINFO is not set
 # CONFIG_DISPLAY_BOARDINFO is not set
+CONFIG_BOARD_LATE_INIT=y
 CONFIG_SYS_MAXARGS=64
 CONFIG_SYS_CBSIZE=512
 # CONFIG_CMD_CONSOLE is not set