hw/ppc: Consolidate ppc440 initial mapping creation functions

Add a utility function and use it to replace very similar
create_initial_mapping functions in 440 based machines.

Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@amd.com>
Tested-by: Edgar E. Iglesias <edgar.iglesias@amd.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
5 files changed