blob: Rename FW_xyz_FDT_OFFSET to FW_xyz_FDT_ADDR

Instead of placing FDT (passed by previous booting stage) at a
location relative to next address we should have absolute
location of placing FDT so that we more freedom of placing FDT.

This will be particularly useful for platforms/boards with
very less RAM (such as Kendryte board).

Due to above motivation, we rename FW_xyz_FDT_OFFSET options
to FW_xyz_FDT_ADDR options and use FW_xyz_FDT_ADDR options as
absolute address for placing FDT.

Signed-off-by: Anup Patel <anup.patel@wdc.com>