ddr

All boards need CONFIG_BOARD_EARLY_INIT_F, and many actively need
CONFIG_BOARD_LATE_INIT. Move both of these into tegra-common.h so that
board config headers don't need to repeatedly define them.

Later commits will add new code in board_late_init() which applies to
all boards, so CONFIG_BOARD_LATE_INIT should be enabled for all Tegra
boards.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>