spl: Drop SPL/TPL_RAM_SUPPORT option for SPL_LOAD_FIT_ADDRESS

All boards which actually define this address enable SPL_LOAD_FIT, or at
least just rely on the default value of 0. So drop the dependency.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>