soc/amd/stoneyridge: clean up southbridge.c

* Limit dependency on vendorcode header files and use defines from
  iomap.h and southbridge.h
* Factor out to functions, device power-on code for AMBA and UART.

BUG=b:69220826
BRANCH=master
TEST=abuild, build Gardenia, build and boot Grunt

Change-Id: Ibcf4d617e2a0a520a6d7e8d0d758d7a9705a84ea
Signed-off-by: Garrett Kirkendall <garrett.kirkendall@amd.corp-partner.google.com>
Reviewed-on: https://review.coreboot.org/25010
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin Roth <martinroth@google.com>
Reviewed-by: Richard Spiegel <richard.spiegel@silverbackltd.com>

0 files changed, 0 insertions, 0 deletions