amd/stoneyridge: Simplify SB link routing

Remove the check for the southbridge link from Stoney Ridge.  The APU
is an SoC which can never be installed in a multi-node system.  It is
pointless to detect and remember the sblink value, which is set by
hardware and comes up 0.  The BKDG marks this as a reserved field vs.
documentation for multi-node-capable Family 15h devices.

Because there is only one option for SB link now, relocate the register
write done by set_vga_enable_reg() and remove the function.

Change-Id: Ie4ce6b5aa847a184534224db302437ff8d37c14b
Signed-off-by: Marshall Dawson <marshalldawson3rd@gmail.com>
Reviewed-on: https://review.coreboot.org/21494
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
1 file changed