fdtdec: Reorder fdtdec_set_carveout() parameters for consistency

The fdtdec_set_carveout() function's parameters are inconsistent with
the parameters passed to fdtdec_add_reserved_memory(). Fix up the order
to make it more consistent.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>