Convert CONFIG_BOARD_LATE_INIT to Kconfig

This converts the following to Kconfig:
   CONFIG_BOARD_LATE_INIT

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/bcm7260_defconfig b/configs/bcm7260_defconfig
index 55e290c..a2707a0 100644
--- a/configs/bcm7260_defconfig
+++ b/configs/bcm7260_defconfig
@@ -11,6 +11,7 @@
 CONFIG_BOOTDELAY=1
 CONFIG_USE_PREBOOT=y
 CONFIG_PREBOOT="fdt addr ${fdtcontroladdr};fdt move ${fdtcontroladdr} ${fdtsaveaddr};fdt addr ${fdtsaveaddr};"
+CONFIG_BOARD_LATE_INIT=y
 CONFIG_HUSH_PARSER=y
 CONFIG_SYS_PROMPT="U-Boot>"
 CONFIG_CMD_ASKENV=y