powerpc/mm: Declare arch_report_meminfo() prototype.

It fixes this W=1 compile error :

../arch/powerpc/mm/book3s64/pgtable.c:411:6: error: no previous prototype for ‘arch_report_meminfo’ [-Werror=missing-prototypes]
  411 | void arch_report_meminfo(struct seq_file *m)
      |      ^~~~~~~~~~~~~~~~~~~

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210104143206.695198-17-clg@kaod.org
1 file changed