libpdbg/p9chip.c: fix ram_setup sequence
libpdbg/p9chip.c: fix ram_setup sequence

This comes from the workbook.

Signed-off-by: Nicholas Piggin <24829078df5003d9dd1dd871ca2aeb0b1cf95ef4@gmail.com>

open-power/pdbg,open-power/pdbg,open-power/pdbg