amd/stoneyridge: Add PSP definitions southbridge and iomap

Define the PSP's BAR3 and BAR3 enable bit.  Define a default base
address for BAR3.

Change-Id: I59a0ec59b7c6bbc6468b3096ec8d025832349f44
Signed-off-by: Marshall Dawson <marshalldawson3rd@gmail.com>
Reviewed-on: https://review.coreboot.org/22250
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
2 files changed