microblaze: Wire memblock_dump_all()

Wire memblock_dump_all() to be able to see the whole memblock allocation.
Dumps are enabled by passing memblock=debug via kernel command line.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Link: https://lore.kernel.org/r/6f480b6010068872f429df69c8894cc3f1f38f46.1645795048.git.michal.simek@xilinx.com