configs: ti: Move FIT image load address to avoid overwrite

configs: ti: Move FIT image load address to avoid overwrite

The FIT image is loaded to 0x8700_0000 followed by extracting from that
several large images also into the 0x8x00_0000 range. Large images
can end up overwriting the FIT image as it is being extracted from.
Move the FIT load address clear out to 0x9000_0000, this will require
a board to have at least 256MB of DRAM, if less then more careful
planning will be required for that platform.

Signed-off-by: Andrew F. Davis <afd@ti.com>