ARM: shmobile: kzm9d: Enable AUTO_ZRELADDR in defconfig

This is required to allow the load address to be supplied
as an environment variable when building a uImage.

LOADADDR=0x40008000 ARCH=arm make uImage

This is necessary since "ARM: shmobile: Remove legacy KZM9D board code"

Signed-off-by: Simon Horman <horms+renesas@verge.net.au>