The maximum spl_size for rk3399 is the internal memory size minus
the size used in bootrom (which usually can get from SPL_TEXT_BASE).
Signed-off-by: Kever Yang <kever.yang@rock-chips.com> Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com> Reviewed-by: Simon Glass <sjg@chromium.org> Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>