[coreboot] v3 add 8131 support

[Myles Watson]

This patch does some minor fixups for 8111 and 8132 and adds support for 8131.

southbridge/amd/amd8132/Makefile:
    Trivial whitespace fix.

southbridge/amd/amd8132/amd8132_bridge.c:
    Remove unnecessary includes and fix enable_resources pointer.

southbridge/amd/amd8111/stage1_smbus.c:
    Remove unnecessary includes.

southbridge/amd/amd8131/apic.dts:
southbridge/amd/amd8131/Makefile:
    Copy file from 8132 with trivial changes.

southbridge/amd/amd8131/amd8131_bridge.c:
    Copy v2 driver file and update like 8132.

Kconfig:
    Add SOUTHBRIDGE_AMD_AMD8131.

Signed-off-by: Myles Watson

Thanks,
Myles