uboot-phytec

armv8/layerscape: remove unnecessary function declares

For the function alloc_stream_ids() append_mmu_masters() and
fdt_fixup_smmu_pcie() there are no related definitions and they
are never called. So the patch removes the unnecessary declares.

Signed-off-by: Minghuan Lian <Minghuan.Lian@nxp.com>
Reviewed-by: York Sun <york.sun@nxp.com>