soc: Add AMD Stoney Ridge southbridge code

Copy the Hudson/Kern code from southbridge/amd/pi/hudson.  This
is the first of a series of patches to migrate Stoney Ridge
support from cpu, northbridge, and southbridge to soc/

Changes:
- add soc/amd/stoneyridge and soc/amd/common
- remove all other Husdon versions
- update include paths, etc
- clean up Kconfig and Makefile
- create chip.c to contain chip_ops

Change-Id: Ib88a868e654ad127be70ecc506f6b90b784f8d1b
Signed-off-by: Marc Jones <marcj303@gmail.com>
Reviewed-on: https://review.coreboot.org/19722
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin Roth <martinroth@google.com>
48 files changed