move CONFIG_BOOTDELAY into a Kconfig option. Used for this
purpose the moveconfig.py tool in tools.

Signed-off-by: Heiko Schocher <hs@denx.de>

Reviewed-by: Tom Rini <trini@konsulko.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Igor Grinberg <grinberg@compulab.co.il>